John Skartveit
email: john.skartveit@nla.no

André Nel
email: anel@mnhn.fr

Revision of fossil Bibionidae (Insecta: Diptera) from French Oligocene deposits

Keywords: Penthetria, Plecia, Bibio, Bibiodes, Dilophus, France, new species, new combination

, nec Brunetti, 1913 is a primary junior homonym and the name must be replaced. The species is moved to the genus Plecia and renamed Plecia theobaldi nom.n.

Introduction

Bibionid flies are very abundant in some European lacustrine deposits from the Oligocene [START_REF] Collomb | March flies and European Cenozoic palaeoclimates (Diptera: Bibionidae)[END_REF], in particular the tropical and subtropical bibionid genus Plecia Wiedemann, 1828 is very abundant in several deposits. A large number of nominal species have been described from these deposits. [START_REF] Evenhuis | Catalog of the fossil flies of the world[END_REF] listed 74 species of Plecia, in addition 28 species of Penthetria, and 57 species of Bibio from European Oligocene fossils. However, a large number of these species descriptions are based on quite incomplete specimens, or the characters used to define species are of taphonomical and not phylogenetic significance. For instance, the relative size and shape of the abdomen is commonly used as a character (e.g. Théobald 1937 p. 331). Flies found in lacustrine deposits have fallen into water. As the fly partly decomposes, the abdomen will swell and get bloated, while the more solidly sclerotised parts (head, thorax and legs) will maintain their shape. Taphonomic compression has also an important effect on the shape of the abdomen, more or less compressed depending on the pressure that the dead animal had to support when embedded in or between the laminae. Thus the apparent size and shape of the abdomen will depend on the time it took before the dead fly was covered by sediment, not on any trait of the living specimen. This was pointed out by [START_REF] Statz | Neue Dipteren (Nematocera) aus dem Oberoligocän von Rott[END_REF] who nevertheless used the relative length of the abdomen as an important character. There is some evidence that a few fossil bibionids were actually brachypterous [START_REF] Skartveit | Revision of Bibionidae (Diptera) named by Oswald Heer from the Miocene of Öhningen, Southern Germany[END_REF], these can however be recognized on their deviant wing shape and venation. [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF] also used the shape of the abdomen together with the colour of the insect body and wings as diagnostic characters. A further difficulty is the fact that in the same outcrop (or even lamina), the preservation of the colours can vary greatly in relation to the epigenisation of the insect.

In modern bibionids descriptions of new species are normally based on male specimens, and characters of the male terminalia are considered very important. In contrast, the majority of species descriptions in fossil bibionids were based on females, partly because these were more numerous in the deposits and partly because they, being somewhat more robust than the males, tended to be better preserved. Distinguishing modern species based on females alone is very difficult in areas where numerous species occur, this is much more so with fossil specimens. [START_REF] Statz | Neue Dipteren (Nematocera) aus dem Oberoligocän von Rott[END_REF] suggested that all descriptions of new fossil bibionid species should be based on females since they are more abundant in impression fossil materials, and the majority of previously described species were obviously based on female specimens. While this would seem a reasonable compromise given the state of the material and the published species, we choose not to follow it since that would differ radically from the strategy chosen in the morphologically similar, recent species, and since it would preclude the use of the systematically very useful male terminalia. Bibionids being often quite abundant in Tertiary fossil insect faunas, there will often be well-preserved males available for study, although they tend to be outnumbered by the females [START_REF] Skartveit | Revision of Bibionidae (Diptera) named by Oswald Heer from the Miocene of Öhningen, Southern Germany[END_REF]. A problem with interpreting male terminalia in fossils is that important components, particularly the gonostylus, have three-dimensional shapes and may appear rather different when viewed from different angles (See [START_REF] Collomb | March flies and European Cenozoic palaeoclimates (Diptera: Bibionidae)[END_REF] for illustrative examples). Modern specimens and amber fossils may be rotated for comparable views, but this is not possible with compression fossils which are basically rather two-dimensional. Thus the terminalia of male bibionids, though well preserved, may be difficult to interpret. One apparently useful character is the length of the gonostylus compared to the width of the hypopygium. This should be used with great caution, though, since the apparent width of the hypopygium is highly dependent on the degree of flattening. It is probably better to base comparisons on the absolute length of the gonostylus. In the subfamily Bibioninae good species-level distinguishing characters are often found in the antennae, legs and wings (pile colour may also be useful but is hardly ever preserved in compression fossils), so distinguishing species based on females is usually achievable. However, the marked sexual dimorphism causes problems in associating male and female specimens. In some cases, it is possible to find laminae with a quantity of males and females obviously of the same species; they died during a swarm. This phenomenon is rather frequent in the Oligocene of Céreste (France). In Bibioninae, species differences in the male terminalia, though constant, are often so slight that they can rarely be used in fossil specimens and only exceptionally well-preserved specimens show these characters with sufficient clarity.

Kleinkembs

Although the locality is actually in Germany, the locality of Kleinkembs, Baden (47.7°N, 7.5°E) is very close to the French border and it is natural to include it in this review, as did [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF] in his review of French Oligocene insects. The site is of Middle Oligocene (33.9-28.4 MYR) age. There are 180 bibionid specimens from Kleinkembs in NMB, many of them well preserved. Numerous species were described from the site by [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF].

Study of the specimens

Specimens were photographed using a digital camera (Olympus E3) equipped with a macro lens (Olympus Zuiko Digital 35 mm. f 2.8) for later study. Total length or wing length (whichever was more accessible) were measured and other measurements were later collected from the photos using these as standards. Thorax length was measured from the anterior margin of pronotum to posterior edge of mediotergite, thorax width as the distance between wing bases in dorsal view. Abdominal width was measured across the third tergite. Length of curved structures (wing veins, gonostyli) was measured along the curve. Wing width was measured at the widest point, which is generally at midwing for Penthetria and Plecia spp., a little more basad for Bibioninae. As usual with fossil insects, the amount of information that can be extracted from a specimen is highly variable, some type specimens are near perfect and others are barely (or not at all) recognizable. For this reason the amount of information available in the description will vary from species to species, it is not possible to be fully consistent except by rejecting a large fraction of the previously described species. We have measured the size of various structures where that is possible, but the measurements given in the descriptions of the various species are frequently collected from different specimens. For this reason, it is not possible to calculate ratios between different measurements from the data as here presented. Drawings were prepared based on the digital photos, and, in some cases, from camera lucida sketches made using a stereo microscope.

Wing vein terminology

Wing vein terminology follows the traditional terminology of [START_REF] Haenni | Morphology and terminology of adult Diptera (other than terminalia)[END_REF]. An alternative classification [START_REF] Wootton | The implications of function on the origin and homologies of the dipterous wing[END_REF] has revised the terminology of the seventh vein reaching the wing edge (CuA1 according to Merz & Haenni), classifying this as a branch of M (as M4), we have chosen not to follow this since the vein in Bibionidae is connected to M only through a fine, transverse vein, whereas a strong longitudinal vein connects it with CuA. The most posterior, long vein is interpreted as CuP in accordance with [START_REF] Wootton | The implications of function on the origin and homologies of the dipterous wing[END_REF]. Vein A1 is rarely possible to see in compression fossils and accordingly we do not include it in the descriptions. The humeral crossvein, Subcosta and the crossvein M-Cu are also frequently faint and difficult to see. They are included in the descriptions where we have been able to trace them, but if they are not mentioned in a description it does not mean that they are absent unless it is specifically stated so.

Radial sector undivided, legs more or less thickened Bibioninae -20

2. Vein R2+3 long, horizontal to oblique Penthetria -3

Vein R2+3 shorter, oblique to vertical Plecia -9

3. Larger species, body length mostly 12-13 mm, female wing light brown, posterior veins colourless. Male gonostylus slender.

Penthetria gigantea

Smaller species, body length mostly < 12 mm -4

4. Vein R2+3 bent near base, sinuous, very long.

Penthetria nervisinuata

Vein R2+3 straight or evenly curved, shorter.

-5

5. Body long and slender (Fig. 10), thorax convex Penthetria graciliventris

Body not conspicuously long and slender -6

6. Wing dark brown fumose.

Penthetria longiventris

Wing hyaline to light brown fumose.

-7

7. Male gonostylus pointed apically. Female sternite VIII without appendages.

-8

Male gonostylus blunt apically. Females unknown.

Penthetria subterranea

Female sternite VIII with a pair of digitiform appendages. Males unknown

Penthetria lugens

8. Wing with basal part of radial sector steep, forming a 45°angle with R1

Penthetria claripennis

Wing with basal part of radial sector forming a less than 30°angle with R1

Penthetria luberonica

9. Wing dark brown fumose, body dark.

-10

Wing light brown fumose to hyaline, body usually lighter coloured -12 10. Larger species, body length 14-15 mm. Female head conspicuously small.

Plecia morio

Smaller species, body length 7-10.

Bibiodes provincialis

Veins Rs and M meet but do not merge. Larger species, 8-12 mm. Antenna slender with 10segmented flagellum.

Bibio major

23. Wing veins blackish, pigmented throughout, pterostigma blackish.

-24

Posterior wing veins colourless, pterostigma less distinctive.

-25 24. Vein CuA1 apically straight.

Bibio spectabilis

Vein CuA1 apically hooked.

Bibio curtisii

25. Veins R-M and basal radial sector more or less equal in length.

-26

Crossvein R-M short, basal radial sector two to three times as long as it. -27 26. Larger (female 10-13 mm), slender species. Male hind tibia strongly clavate.

Bibio aquaesextiae

Smaller (female 6.7-9 mm), robust species. Male unknown.

Bibio dislocatus

27. Wing yellowish fumose with concolourous veins and pterostigma. Larger species, 8-13 mm.

Bibio baumbergeri

Wing light brown with dark brown R-veins and dark pterostigma. On average smaller species, 6-9 mm.

Bibio celasensis

Genus Penthetria Meigen, 1803

While it is straightforward to distinguish the genera Penthetria and Plecia in recent species, this is not always so with fossils. In the recent species, it is most convenient to identify the genera based on the shape of the vein R2+3, which is long and horizontal in Penthetria, short and steep in Plecia. However, in fossil species the shape of R2+3 (sometimes named R3+4) varies continuously [START_REF] Rice | Fossil Bibionidae (Diptera) from British Columbia[END_REF] and it is not possible to draw a non-arbitrary line between Penthetria and Plecia wing venation. [START_REF] Handlirsch | Die fossilen Insekten und die Phylogenie der rezenter Formen[END_REF] chose to put all fossil bibionids with forked Radial sector in the genus Penthetria, this may be warranted given the limited information available on the morphology of most of the fossil species. However, some fossil species are quite typical of the genus Plecia. In recent species, male terminalia in Plecia spp., though highly variable, is almost always decidedly different from the plesiomorphic pattern invariably found in Penthetria species. However, many fossil species that habitually conform to Plecia have plesiomorphic terminalia, with digitiform gonostyli which are attached distally on the gonapophysis and are directed mesally (e.g., [START_REF] Skartveit | Fossil Bibionoidea (Diptera: Hesperinidae and Bibionidae) from Baltic amber[END_REF]. Typical Penthetria males can still be recognized on the very robust, pilose, curved gonostyli, but this is apparent only in very well preserved fossils, whereas a large proportion of the named species have been described from females or poorly-preserved males. One often has to resort to general habitus to assign these species to genus since characters of the terminalia are not available. Penthetria species are generally larger (most species more than 10 mm), more gracile with markedly longer legs, slender male abdomens, the wings are longer, slender in the males and notably large in the female, usually fumose. Plecia species are little beyond apex of R4+5. Pterostigma not conspicuous. R2+3 almost straight, slightly curved. R4+5 distally curved. Fork of M long and rounded. CuA2 curved basad in distal part. Vein measurements in Table 1.

Legs: Dark brown, relatively short, slender. Fore femur 2.1-3.2 mm (N=2), fore tibia 2.4-3.0 mm (N=2), hind femur 2.4-3.5 mm (N=3), hind tibia 2.3-4.0 mm (N=4).

Abdomen: Brown. , width 2.2-3.2 mm (N=5).

Terminalia: Tergite IX mesally with a deep, U-shaped excavation. Cerci rather small, two-segmented, slender.

Penthetria luberonica sp.n. (Figs. 12-13, 90-94)

Material examined: Holotype (male) FSL 140048b Paratype (males) FSL 140050, FSL 140053g.

Additional material (7 males 20 females): FSL 140009, 140010, 140021, 140023, 140027, 140034, 140036, 140038, 140041, 140046, 140048a, 140049, 140053, 140279, 140307, 140312.

Etymology:

The species is named after the Lubéron Massive, where the outcrop is situated.

Localities: Vitrolles.

Diagnosis: A small Penthetria, total length 7-9 millimetres. Antennal flagellum 9-segmented. Wing light brownish fumose, R2+3 of medium length, slightly sinuate. Male gonostylus robust, curved and pointed, epandrium dome-shaped. Most similar to P. claripennis, but recognized by basal part of Rs being nearly parallel to M.

Description:

Male: Total length 7.0-9.5 mm (N=8 1.

Legs: Pale brown, not well preserved in any of the specimens at hand.

Abdomen: Length 4.4-6.4 mm (N=7), width 0.9-1.0 mm (N=4). Brown, quite slender.

Terminalia (fig. 92): Hypopygium width 0.58-0.93 mm (N=6). Gonostylus length 0.43-0.47 mm (N=2). Blackish-brown. Epandrium presumably dome-shaped. Gonostylus robust, apically curved and sharply pointed.

Female: Total length 6.7-8.2 mm (N=11).

Head (fig. 94): Length 0.67-0.76 mm (N=2), width 0.67-0.94 mm (N=8). Dark brown, presumably black in life. Flagellum probably 9-segmented, length 0.54-0.62 mm (N=3).

Thorax: Length 1.9-2.4 mm (N=12), width 1.5-1.9 mm (N=7). Dark brown, presumably black in life.

Haltere pale brownish.

Wing (fig. 93): Length 6.1-7. A medium-sized Penthetria, rather stocky for the genus, entirely black as usual for the genus. The shape of vein R2+3 is characteristic: it is vertical at base, then turns 90° and runs parallel to R4+5 in the basal half, then turns forwards, meeting Costa at an almost 45° angle. Localities: Aix-en-Provence, Céreste.

Other material (MNHN): Males: Aix 779, 884, 974, 1085, P26. Females: Aix 332, 428, 645, 752, 799, 890, 926, 965, 1013, 1061, 1322, 1337, 1347, 1404. (RGL) Céreste 662. Isolated wing: Céreste 192. Female, labeled 164 (ETHZ, fig. 15).

Diagnosis:

The species is easily recognized by the long, horizontal vein R2+3, which is sharply bent basally and a bit sinuous in the middle. It is the only species in the French Oligocene material with a typical Penthetria wing venation. Specimens with preserved pigmentation are entirely dark with blackish-fumose wings.

Redescription:

Male: Total length 8.2-12.0 mm (N=5). The specimens are of a uniform, brown colour, probably not original colour.

Head: Length 0.96-1.30 mm (N=5), width 1.03-1.41 mm (N=4). Antenna robust, segments not possible to count.

Thorax: Length 2.2-2.9 mm (N=5), width 1.7 mm (N=1, smallest specimen).

Wing (fig. 102): Length 6.7-9.1 mm (N=4), width 2.2-2.9 mm (N=3), length/width = 2.98-3.30 (N=3). No pigment preserved in membrane, R-veins brown, posterior veins colourless. Costa extends to apex of R4+5. Humeral vein present, Subcosta terminating at origin of R2+3. Pterostigma oval, brown. R2+3 long, originating at base of pterostigma, bent in a right angle near base. Wing vein measurements in Table 1.

Legs: Slender, first tarsomere of hind leg slightly swollen and spindle-shaped. Fore femur 2.2 mm (N=1), fore tibia 2.2-2.3 mm (N=2), hind femur 2.7-3.5 mm (N=3), hind tibia 2.5-3.8 mm (N=3).

Abdomen: Length 5.4-8.0 mm (N=5), width 1.1-1.6 mm (N=2). Cylindrical. Terminalia (fig. 101): Gonostylus digitiform, curved, pointed. Epandrium wide, dome-shaped. Hypopygium width 0.83-1.15 mm (N=4), gonostylus length 0.43 mm (N=1).

Female: Total length 7.5-12.0 mm (N=16). Holotype and one paratype very dark, probably the original colour. Most of the other specimens have little or no pigment preserved. Head (fig. 99): Length 0.77-1.16 mm (N=11), width 0.82-1.28 mm (N=17). Rounded. Complex eye medium-sized, slightly protruding. Ocellar triangle prominent but not very tall. Antenna robust, flagellum probably 8-segmented.

Thorax: Length 1.9-3.1 mm (N=16), width 1.7-2.6 mm (N=15). Sulci prominent. Haltere dark brown.

Wing (figs. 98, 100): Length 7.0-10.5 mm (N=18), width 2.7-3.9 mm (N=16), length/width = 2.44-3.00 (N=14). Blackish fumose, R-veins dark, posterior veins concolourous with membrane. Costa terminates at apex of R4+5. Humeral vein present, Subcosta terminating at or slightly beyond origin of R2+3. Pterostigma oval, black. CuA-veins conspicuously strong. Vein R2+3 long and sinuous, basally vertical, bent 90° and then running parallel to R4+5 before bending toward costa in distal half. Relative length of stem and fork of CuA apparently quite variable. CuA2 apically curved basad. Wing vein measurements in Table 1.

Legs: Slender, covered with short erect dark pile. Length of fore femur 2.0-2.6 mm (N=5), fore tibia 1.8-2.6 mm (N=6), hind femur 2.1-3.1 mm (N=5), hind tibia 1.9-3.5 mm (N=6).

Abdomen: Length 5.1-8.3 mm (N=14), width 1.9-2.8 mm (N=13). Cylindrical.

Terminalia: Three spermathecae present. Cerci two-segmented, small and slender.

Penthetria subterranea [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF] Localities: Kleinkembs, Aix-en-Provence.

Diagnosis: A medium-sized Penthetria (10-11 mm), male wing yellowish brown fumose. Vein R2+3 nearly straight. Male gonostylus digitiform, apically blunt.

Redescription:

Male: Total length 8.5-11.0 mm (N=7). Brown.

Head: Length 1.0-1.2 mm, width 1.1-1.4 mm (N=4). Relatively small, broadly oval. Complex eye dichoptic? Flagellum 8-segmented, length 0.5 mm (N=1).

Thorax: Length 2.3-2.8 mm (N=7), width 1.8-2.0 mm (N=2). Black, convex. Sulci not particularly deep and conspicuous. Pile not conspicuous. Haltere brown.

Wing (fig. 103): Length 6.7-8.9 mm (N=5), width 2.5-2.9 mm (N=4), length/width = 2.89-3.22 (N=3). Yellowish fumose, rather narrow. Pterostigma small, pale brown. R-veins brown, posterior veins colourless. Costa extends to more than half-way between apices of R4+5 and M1. Subcosta long and prominent, humeral vein present. R2+3 oblique, nearly straight. Wing vein measurements in Table 1.

Legs: Slender, yellowish, tarsi and apex of tibiae darker. Length of fore femur 1.9 mm (N=1), fore tibia 2.1-3.6 mm (N=3), hind femur 2.4-3.7 mm (N=3), hind tibia 2.6-3.6 mm (N=2), hind first tarsomere 1.1 mm (N=1).

Abdomen: Length 5.4-9.4 mm (N=7), width 1.2-1.5 mm (N=6). Long, slender, cylindrical. Pile not conspicuous.

Terminalia (figs. 104-105): Hypopygium width 0.7-1.4 mm (N=6). Epandrium apparently undivided with slightly convex posterior edge. Gonostylus 0.41-0.62 mm long (N=4), digitiform, curved, apically blunt.

Female: Total length 6.0-9.6 mm (N=9)

Head: Length 0.59-0.80 mm (N=6), width 0.71-0.94 mm (N=5). Black. Antenna robust, flagellum 0.47-0.57 mm long (N=2), 8-segmented?

Thorax: Length 1.8-2.5 mm (N=11), width 1.6-1.9 mm (N=4). Dark yellowish-brown. Haltere pale brownish.

Wing (fig. 106): Length 5.8-8.2 mm (N=10), width 2.2-3.2 mm (N=7), length/width = 2.57-2.99 (N=7). Hyaline to light brownish fumose, veins light brown. Venation as in male except that R2+3 is shorter and steeper. Wing vein measurements in Table 1.

Legs: Scarcely preserved in the specimens at hand. Yellowish-brown. Length of fore tibia 1.8-2.0 mm (N=2).

Abdomen: Length 3.7-6.4 mm (N=10, obviously shrunk in some specimens), width 1.5-1.9 mm (N=4). Brown.

Terminalia: Cercus rather long, two-segmented, terminal segment slender.

Genus Plecia Wiedemann, 1828

In the 19 th Century, fossil Plecia species were mostly placed in the genus Protomyia Heer, though many Penthetria species were also included in this genus.

Plecia assonensis Gentilini, 1993 (Figs. 19, 107-109)

Plecia assonensis Gentilini 1993: 161.

Possibly a synonym of Plecia livida, but the pointed gonostylus might be diagnostic together with the straight, oblique vein R2+3 and the indistinctive pterostigma.

Material examined: (RGL) Dauphin 33, Bois d'Asson 34, Bois d'Asson 81

Localities: Bois d'Asson

Diagnosis: A small Plecia (wing length approximately 5 mm). Antennal flagellum 9-segmented. Vein R2+3 straight and oblique. Male gonostylus stout digitiform.

Redescription:

Male: Total length 5.0-8.5 mm (N=2, the former specimen obviously shrunk)

Head: Length 0.81 mm (N=1), width 0.86-1.21 mm (N=2). Antennal flagellum 9-segmented according to Gentilini (1993: 161), not possible to see in the specimens at hand.

Thorax: Length 1.7-2.9 mm (N=3), width 1.7-2.2 mm (N=2). Brown. Haltere pale.

Wing (fig. 107): Length 5.1-5.7 mm (N=3), width 1.7-2.5 mm (N=2), length/width = 2.31-3.01 (N=2). Pale brownish, almost hyaline, veins brown, slender, R-veins not notably stronger than posterior veins. Costa extends to a little beyond apex of R4+5. Subcosta fine, terminates approximately at fork of M, humeral vein present. Vein R2+3 short, nearly straight and oblique, R4+5 slightly curved. Pterostigma small, light brown, indistinctive. Wing vein measurements in Table 2.

Legs: Light brownish, getting darker apicad. Hind femur apparently pale with darker apex.

Abdomen: Length 2.9-5.8 mm (N=3), width 0.9-1.4 mm (N=3). Brown, relatively broad. Penthetria edwardsii [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF] Plecia edwardsii [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]; Brongniart, 1878: XLVIII. Plecia dilatativentris Théobald, 1937: 338-339. Syn.n.

The species was described from Radoboj and Aix-en-Provence. Heer in his original description did not fix any holotype, but the description was made with reference to Buckland's (1837, Pl. 46) illustration of a specimen from Aix-en-Provence, so this should be regarded as the type. We could not find this specimen in NHM. The name has generally been spelled bucklandi as the species was named after the Rev. William Buckland. However, the somewhat awkward form buklandi was used in the heading of the original description (Heer 1849 p. 238). The form bucklandi was however, used in the legends to the plates (Heer 1849, Pl. XVI, Fig. 22) and in all subsequent treatises.

Material examined: Two female specimens of Protomyia bucklandi from Aix in ETHZ, not among those illustrated by Heer (1849, Pl. XVI, Fig. 22), but labeled in Heer's handwriting. Figured specimen (female) FSL 391930 (A 25). Syntype (female) of Protomyia elegans (NHMUK In 39832). Syntype (female) of Protomyia gracilis (NHMUK In 38765). One specimen labeled as Protomyia gracilis in ETHZ, not the one illustrated by Heer but the name is written in Heer's handwriting. Syntypes (3 females) of Bibio edwardsii (MNHN R 06671, R 06669). Holotype (female) of Plecia dilatativentris FSL 391924. Paratypes (2 females) of Plecia dilatativentris MNHN B 24418. Additional material (6 females) FSL 391928, 391931-391935.

Localities: Aix-en-Provence, Corent.

Diagnosis: A medium-large (7.5-10.5 mm) Plecia, body and wings dark brown, probably black in life. Antennal flagellum probably 8-segmented. Fore femorae apparently pale brown.

Redescription:

Male unknown

Female Total length 7.5-10.5 mm (N=11), dark brown, presumably black in life.

Head (figs. 112-113): Length 0.87-1.14 mm (N=5), width 0.96-1.35 mm (N=5). Rather short and broad, complex eye a little prominent. Antenna rather short, flagellum probably 8-segmented, cylindrical, 0.57-0.71 mm long (N=4).

Thorax: Length 2.2-3.0 mm (N=9), width 1.7-2.6 mm (N=4). Black. Haltere brown.

Wing (figs. 110-111): Length 7.0-9.2 mm (N=10), width 2.5-3.7 mm (N=8), length/width = 2.45-3.25 (N=8). Blackish fumose, veins brownish black, prominent throughout wing. Pterostigma indistinctive due to generally dark membrane. Subcosta prominent, long, humeral vein present. Costa extending to apex of R4+5. R2+3 a little curved, oblique. Wing vein measurements in Table 2.

Legs: relatively short, slender, femorae brownish, tibiae and tarsi black. Length of fore femur 1.7 mm (N=1), fore tibia 1.6-2.2 mm (N=5).

Abdomen: Length 5.2-7.7 mm (N=8), width 1.8-2.8 mm (N=6), black, cylindrical.

Terminalia: cerci short and indistinct.

Plecia conica Théobald, 1937 (Figs. 29-30, 114-118) Plecia conica [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF]: 232. Plecia haennii Gentilini, 1993: 164. Syn.n.

Material: Holotype (male) of Plecia conica NMB F1398/1, paratype (male) of Plecia conica NMB F1398/2. Non-type material (3 males) NMB F2090, (RGL) Dauphin 12, Saint-Maime 23 Plecia conica may quite possibly be the male of Plecia foersteri (next species).

Localities: Bois d'Asson, Kleinkembs

Diagnosis: A small Plecia (total length 5-7 mm). Antennal flagellum 8-segmented. Male epandrium dome-shaped, gonostylus very robust, apically expanded.

Redescription:

Male (figs. [29][30][115][116]: Total length 5.0-7.0 mm (N=4).

Head: Length 0.85-0.90 mm (N=2), width 0.93 mm (N=1). Antennal flagellum 8-segmented. Ocellar tubercle rather small.

Thorax: Length 1.7-2.2 mm (N=3), width 1.5 mm (N=1). Black. Haltere yellowish-brown.

Wing (fig. 114): Length 4.8-5.0 mm (N=3), width 2.0-2.1 mm (N=2), length/width = 2.39-2.50 (N=2), elliptical. Light brownish fumose, veins fine and light brown. Pterostigma very indistinctive. R2+3 straight and oblique. Apex of R4+5 slightly curved.

Legs: Slender, pale brown. Length of fore tibia 1.6 mm (N=1), hind femur 1.9 mm (N=1), hind tibia 2.0 mm (N=1), hind first tarsomere 0.7 mm (N=1).

Abdomen: Length 3.3-4.6 mm (N=3). Brown, conical. Théobald (1937: 137 and 231) described Plecia splendida with two "holotypes" (should be syntypes), one from Kleinkembs and the other one from Célas. We have studied the former but did not succeed in locating the latter, which may be lost. The holotype of Protomyia rubescens is not recognizable, as was also commented on by [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF]. He therefore (presumably) designated a "hypotypoide" for "Plecia cf. rubescens" (NHMB F1395/1), this specimen has no type status but is useful in clarifying Théobald's concept of the species.

Additional material (28 females): NMB F1395/1, F1410, F1411/1-22, F1412, F2048, F2175, F2223, F2368.

Localities: Kleinkembs, Ronzon, Célas.

Diagnosis: A small-medium sized Plecia (wing length 4.9-7.8 mm). Antennal flagellum 8-segmented. Thorax black, abdomen brown, wing light brownish fumose.

Redescription:

Male unknown. There is one male specimen (NHMB F 2090) in NHMB labelled as Plecia cf.

rubescens, but it is highly uncertain if this is conspecific with the females.

Female: Total length 6.2-8. Localities: Kleinkembs, Aix-en-Provence. The type is from Rott, Germany.

Diagnosis: A rather small Plecia, total length 4.8-6.5 mm. Antennal flagellum rather long, 9segmented. It can be distinguished from Plecia livida on the longer antenna and by the wider wing which is darkened anteriorly.

Redescription:

Male unknown Female: Total length 4.8-6.8 mm (N=14).

Head (fig. 127): Length 0.55-0.85 mm (N=8), width 0.74-1.12 mm (N=12). Black, rather wide, rounded. Antennal flagellum rather long, cylindrical, 9-segmented. Ocellar triangle prominent.

Thorax: Length 1.5-2.1 mm (N=15), width 1.3-1.6 mm (N=6). Black. Sulci deep. Haltere brown.

Wing (fig. 126): Length 4.9-6.7 mm (N=7), width 2.0-3.0 mm (N=5), length/width = 2.17-2.47 (N=5). Oval, comparatively broad, anterior margin conspicuously curved. Light brown fumose, anterior part darkened, veins brown throughout. Costa extends almost to apex of M1. Pterostigma brown, does not extend below R1, conspicuous. R2+3 with a kink in basal fourth, otherwise nearly straight, oblique. Crossvein M-Cu some distance from base of CuA1. Wing vein measurements in Table 2.

Legs: Dark brown, slender. Hind tibia 1.9 mm (N=1).

Abdomen: Length 3.2-4.6 mm (N=14), width 1.5-1.8 mm (N=7). Blackish brown.

Terminalia (fig. 128): Cerci small, rounded triangular.

Plecia larguensis

Localities: Bois d'Asson

Diagnosis: A rather small species (6-7.5 mm). The species can be recognized on the hooked, pointed gonostyli and the epandrium bearing three long projections, further on the very short, nearly vertical vein R2+3 and the large, light brown pterostigma. The female is unknown, most likely rather similar to Plecia livida.

Redescription:

Male: Total length 6.0-7.5 mm (N=5).

Head (fig. 130): Length 0.86-1.02 mm (N=3), width 0.84-1.02 mm (N=3). Antennal flagellum cylindrical, 9-or 10-segmented. Ocellar tubercle rather tall, rounded. Palp robust. Rostrum a little elongated, about two thirds as long as complex eye.

Thorax: Length 1.6-1.9 mm (N=5). Dark reddish brown.

Wing (fig. 129): Length 4.9-5.4 mm (N=5), width 1.9-2.1 mm (N=5), length/width = 2.42-2.65 (N=5). Light brownish fumose, pterostigma large, oval and light brown. Veins brown throughout, Rveins scarcely darker than posterior veins. Costa extends almost half-way between apices of R4+5 and M1. Subcosta fine and indistinctive. R2+3 short, nearly vertical, R4+5 nearly straight. Wing vein measurements in Table 2.

Legs: Reddish brown, femorae paler in basal half. Slender throughout. Fore femur 1.6-2.2 mm (N=4), fore tibia 1.9-2.1 mm (N=2), hind femur 2.2 mm (N=2), hind tibia 2.2-2.3 mm (N=2), hind first tarsomere 0.8 mm (N=1).

Abdomen: Length 3.9-4.9 mm (N=5). Brown, slender.

Terminalia (fig. 131): Hypopygium width 0.70-0.95 mm (N=4). Epandrium small, with three long, digitiform projections. Gonostylus 0.37-0.49 mm long (N=4), apically curved and sharply pointed.

Female unknown. The material from Bois d'Asson contains numerous females which are seemingly rather homogenous morphologically. This material presumably contains females of all the four nominal species named by [START_REF] Gentilini | New species of Plecia from the Oligocene of Southeastern France[END_REF], as well as Plecia livida.

Legs: Black. Hind femur moderately clavate, otherwise slender. Length of fore femur 2.0 mm (N=1), fore tibia 1.7-2.9 mm (N=4), hind femur 2.8 mm (N=1), hind tibia 2.8-3.2 mm (N=2).

Abdomen: Length 5.7-8.7 mm (N=6), width 2.1-3.3 mm (N=3). Black.

Terminalia: Cerci small and rounded.

Plecia maimensis Gentilini, 1993 (Figs. 45-46, 149-153) Plecia maimensis Gentilini, 1993: 158. We have not studied the type of this species. It is possibly a synonym of Plecia livida, but this is uncertain. Unique among fossil bibionids, this species was described from a male and female specimen in copula, thus the association of male and female is less tentative than in the other fossil species.

Material (tentative)

Localities: Bois d'Asson

Diagnosis: The species is quite similar to Plecia livida, but the rounded lobe at the base of the gonostylus in the male and the slight kink in Rs at the furcation with R2+3 in the female may be diagnostic for the species.

Redescription:

Male: Abdomen: Length 3.1-5.9 mm (N=7). Brown, conical.

Terminalia (fig. 152): Hypopygium width 0.75-0.85 mm (N=4). Dark brown. Epandrium domeshaped, apically with three short, knob-like points. Gonostylus 0.32-0.57 mm long (N=6), slender, digitiform, slightly curved, basally with a rounded, knob-like dorsal lobe.

Female: Total length 7.0-9.5 mm (N=9) Head (fig. 151): Length 0.81-0.85 mm (N=2), width 0.75-1.04 mm (N=7). Dark brown, rounded, a little wider than long. Complex eye flat, about as long as temples. Antenna slender and pointed, flagellum 7-or 8-segmented.

Thorax: Length 1.9-2.9 mm (N=8), width 1.5-2.1 mm (N=6). Dark brown. Haltere light brown.

Wing: Length 5.9-8.1 mm (N=9), width 2.3-3.2 mm (N=9), length/width = 2.31-2.71 (N=9). Light brownish fumose, veins brown. Pterostigma light brown, rather indistinctive. Costa extends half-way between apices of R4+5 and M1. Rs with a little kink where R2+3 branches off. R2+3 moderately long, strongly curved basally. R4+5 moderately curved apically. Crossvein R-M vertical. Wing vein measurements in Table 3.

Legs: Dark brown.

Abdomen: Length 4.5-7.2 mm (N=9), width 1.5-2.4 mm (N=8). Reddish brown, robust.

Terminalia (fig. 153): Cerci large and prominent, two-segmented.

The sexual size dimorphism of this species was commented upon by [START_REF] Gentilini | New species of Plecia from the Oligocene of Southeastern France[END_REF]. Such a size difference is possible due to the large variability in size in bibionids, and it is probably as common a trait among fossil bibionids as it is among recent ones. Caution is warranted when trying to associate male and female specimens since females may be considerably larger than conspecific males. This trend is not universal, however, since in many recent species females are smaller than males at least with respect to body length. Localities: Aix-en-Provence. Also from Rott, Germany.

The species was described from Radoboj, but we did not find the type specimen in SLJG nor in NHMW. However, the specimen recorded by Heer (1856: 33) from Aix-en-Provence is easily recognizable on being considerably larger than all other specimens recorded by Heer from Aix. The specimens fit Heer's description well.

Diagnosis: A large (13-15 mm), dark Plecia species with dark wings which are darkened in the anterior half, at least in females. The species is easily separated from the other species from French Oligocene sediments by its size. The body proportions of the female are characteristic, with a very small head and large, cylindrical abdomen. Antennal flagellum is cylindrical and nine-segmented. Male: terminalia with long, slender and nearly straight gonostyli.

Redescription:

Male: Total length 13.5-14.0 mm (N=3 Legs: Femorae and tibiae yellowish brown, tarsi dark brown, presumably black in life. Slender throughout, relatively short. Fore femur 3.1 mm (N=1), fore tibia 3.6 mm (N=1), hind tibia 4.6 mm (N=1).

Abdomen: Length 9.9-11.8 mm (N=7), width 4.1-4.2 mm (N=2). Cylindrical, dark brown, probably black in life. Tergites and sternites with rather long, brown pile.

Terminalia: Cerci rather small, apically rounded.

(N=2), width 0.46 mm (N=1), hind femur length 2.2-3.5 mm (N=4), width 0.59-0.69 mm (N=4), hind tibia length 2.5-3.6 mm (N=4), width 0.41-0.58 mm (N=4).

Abdomen: Length 6.4-9.4 mm (N=5), width 2.1-3.2 mm (N=4). Relatively slender, cylindrical.

Colour probably light brown.

Terminalia: Three spermathecae present as usual. Cerci small, rounded.

Discussion: None of the specimens at hand show good colour preservation and it is possible that colours have been considerably darker in life. Localities: Kleinkembs, Aix-en-Provence.

Bibio baumbergeri

Diagnosis: A medium-sized to large (8.3-13 mm), robust Bibio. Antennal flagellum 7-segmented.

Wing hyaline to yellowish fumose with concolourous veins, pterostigma indistinctive, crossvein R-M about one third as long as basal Rs. Legs yellowish-brown in female, black in male, protibial spur about half as long as anterior spine.

Redescription:

Male: Total length 8.3-10.3 mm (N=4).

Head: Black. Ocellar triangle low and inconspicuous.

Thorax: Length 2.7-2.9 mm (N=3), width 2.3 mm (N=1). Black, haltere pale yellowish.

Wing (fig. 165): Length 6.8 mm, width 2.8 mm (N=1). Hyaline, R-veins brown, fine, posterior veins colourless. Basal section of R4+5 about three times as long as R-M. Wing vein measurements in Table 4.

Legs: Black. Fore femur 2.0-2.3 mm long, 0.7 mm wide (N=2). Hind femur stout, clavate, hind tibia slender. Length of hind femur 2.4-3.5 mm, width 0.5-0.6 mm (N=3), length of hind tibia 2.2-2.9 mm (N=2).

Abdomen: Black.

Terminalia (fig. 171): Not well preserved in any of the specimens at hand. Epandrium bilobate with wide, U-shaped cleft between lobes.

Female: Total length 9.3-13.0 mm (N=9).

Head (fig. 167): Length 1.2-1.6 mm (N=4), width 1.1-1.2 mm (N=2), longer than broad, nearly rectangular. Complex eye small and prominent. Ocellar tubercle rather small. Antenna rather small.

Thorax: Length 2.7-4.0 mm (N=8), width 2.7 mm (N=1). Black.

Wing (fig. 166): Length 8.0-10.7 mm (N=8), width 3.1-3.7 mm (N=6 15,17,19,22,23,27,28,42,48,49,52,60,62,66,83,93,101,107,110,121,127,130,132,137,141,160,167, Célas 1, 2 females of uncertain origin.

Localities: Célas, Camoins, Monteils

Diagnosis: A medium-sized (6-9 mm) Bibio. Antenna short and robust, flagellum 7-segmented. Legs with femorae black, stout and clavate. Protibial spur about one third as long as anterior spine. Wing hyaline with dark R-veins, posterior veins colourless, basal part of Rs two to three times as long as R-M.

Redescription:

Male (fig. 173): Total length 6.0-7.5 mm (N=7).

Head: Length 1.04-1.17 mm (N=5), width 1.17 mm (N=1). Antenna short and robust, flagellum probably 7-segmented.

Thorax: Length 2.1-2.5 mm (N=5). Dark brown, presumably black in life. Haltere pale.

Wing (fig. 172): Length 4.1-5.2 mm (N=3), width 1.9 mm (N=1). R-veins brown, posterior veins colourless. Costa extends slightly beyond R4+5. Basal Rs approximately as long as R-M. Pterostigma rather small, brown, distinctive.

Legs: Hind femur clavate, hind tibia apically truncate, rather slim. Legs uniformly dark brown. Fore femur 1.3-1.7 mm long (N=4), 0.44-0.58 mm wide (N=4), fore tibia 1.4 mm long (N=1), hind femur 1.9-2.2 mm long (N=5), 0.42-0.55 mm wide (N=5), hind tibia 1.9-2.0 mm long (N=3), 0.35-0.38 mm wide (N=3), hind first tarsomere 0.67 mm long (N=1).

Abdomen: Length 3.6-5.4 mm (N=5). Relatively slender.

Teminalia (fig. 176): Hypopygium width 0.80-0.84 mm (N=2). Gonostylus rather short, curved and digitiform as usual for genus.

Female (fig. 174): Total length 7.5-11.0 mm (N=28).

Head (fig. 175) Length 1.04-1.38 mm (N=24), width 0.81-1.21 mm (N=4). Antenna rather short, flagellum 7-segmented, 0.41-0.58 mm long (N=5). Ocellar tubercle low, not prominent. Complex eye medium-sized.

Thorax: Length 2.1-2.9 mm (N=28). Dark brown to black, probably black in life. Haltere pale brown.

Legs: Femorae dark brown, probably black in life, tibiae and tarsi brown. Femorae stout and spindleshaped, hind tibia rather slender, tarsi slender. Protibia stout, spur short, approximately 1/3 the length of spine. Fore femur 1.5-1.8 mm long (N=16), 0.54-0.86 mm wide (N=16), fore tibia 1.6-1.8 mm long (N=4), hind femur 1.9-2.7 mm long (N=24), 0.47-0.65 mm wide (N=25), hind tibia 1.9-2.6 mm long (N=24), 0.25-0.48 mm wide (N=22), hind first tarsomere 0.59-0.73 mm long (N=11). The great variability in leg width is probably due to variations in the angle in which the legs are preserved, this is very difficult to judge in flattened fossils.

Wing: Length 5.4-7.3 mm (N=15), width 1.9-2.8 mm (N=10), hyaline, R-veins brown, posterior veins pale brown to colourless. Pterostigma rather small, brown. Basal part of Rs approximately as long as R-M.

Abdomen: Length 4.1-7.8 mm (N=26), cylindrical, rather stout, brown.

Terminalia (fig. 177): Relatively small and inconspicuous, cerci rounded. N=3), fore tibia 1.4-1.7 mm long (N=2), hind femur 2.4-3.6 mm long (N=7), 0.47-0.66 mm wide (N=7), hind tibia 2.7-3.7 mm long (N=5), 0.50-0.58 mm wide (N=5), hind first tarsomere 0.9-1.0 mm (N=2).

Bibio curtisii

Abdomen: Length 5.6-6.9 mm (N=10), width 1.6-2.0 mm (N=5). Dark brown, presumably black in life.

Terminalia (fig. 183): Epandrium 0.97-1.16 mm wide (N=5), with wide, shallow, U-shaped emargination, lateral lobes short and blunt. Gonostylus robust, of the typical shape for the genus.

Female: Total length 10.0-12.0 mm (N=6).

Head: Length 1.08-1.22 mm (N=3), width 1.05-1.30 mm (N=2). Antennal flagellum 7-segmented. Thorax: Length 2.9-3.8 mm (N=6), width 2.6-2.7 mm (N=2). Dark brown, presumably black in life.

Haltere brown.

Wing (fig. 179): Length 7.8-9.9 mm (N=6), width 3.2-3.5 mm (N=5), length/width = 2.44-2.82 (N=5). Light brownish hyaline, veins strong and blackish throughout, pterostigma blackish. Venation as in male. Wing vein measurements in Table 4.

Legs: Dark brown, presumably black in life. Hind femur robust, clavate, hind tibia slender. Fore femur length 1.8-2.3 mm (N=5), width 0.59-0.77 mm (N=3), fore tibia length 1.8-2.3 mm (N=4), hind femur length 2.4-3.2 mm (N=4), width 0.54-0.64 mm (N=4), hind tibia length 2.5-3.2 mm (N=5), width 0.32-0.43 mm (N=3).

Abdomen: Length 6.7-8.4 mm (N=6), width 2.3-2.9 mm (N=3). Dark brown, presumably black in life. Parallel-sided, the two terminal tergites narrower. Cerci prominent, pointed. Additional material (3 females) NMB F1385/1-2, F1386/1-2.

Bibio dislocatus

Localities: Kleinkembs.

Diagnosis: A medium-sized (8.0-9.0 mm), robust Bibio. Antennal flagellum possibly 7-segmented. Fore tibia with spur about half as long as anterior spine. Wing hyaline, veins pale, pterostigma indistinct, crossvein R-M about as long as basal section of Rs.

Redescription:

Male unknown.

Female (fig. 185): Total length 8.0-9.0 mm (N=3), robust. Entirely black.

Head (fig. 186): Length 0.95-1.03 mm (N=4), width 1.06 mm (N=1). Black, widest behind middle, considerably narrowing forwards. Ocellar tubercle indistinct. Antenna rather small, flagellum possibly 7-segmented, 0.63 mm long (N=1).

Thorax: Length 2.4-2.6 mm (N=4). Black, relatively flat dorsally.

Wing (fig. 184): Length 5.9-7.5 mm (N=2). Hyaline, R-veins light brown, posterior veins colourless. Pterostigma pale brown, scarcely visible. Costa extends slightly beyond apex of R4+5. Basal section of Rs subequal to crossvein R-M.

Legs: Brown to black, most likely all black in life. Fore tibia with spur a little over half as long as spine. Femorae strongly clavate, hind tibia and all tarsi slender. Fore femur 1.6-1.7 mm long (N=3), 0.58-0.71 mm wide (N=3), fore tibia 1.6-1.7 mm long (N=3), hind femur 2.1-2.3 mm long (N=4), 0.32-0.38 mm wide (N=4), hind first tarsomere 0.66-0.77 mm long (N=4), 0.25 mm wide (N=1).

Abdomen: Length 5.6-6.2 mm (N=3). Brown, most likely black in life, cylindrical, rather stout.

Terminalia (fig. 187): Cerci small and rounded.

Bibio fusiformis Heer, 1849

This species was described from the Miocene of Öhningen, Southern Germany and redescribed by [START_REF] Skartveit | Revision of Bibionidae (Diptera) named by Oswald Heer from the Miocene of Öhningen, Southern Germany[END_REF]. The species was recorded with some doubt from Aix-en-Provence by Heer (1856: 33). We have not seen any specimens of this species from French localities and judging from Heer's (1856) brief description of the specimen it is almost certainly not identifiable at the species level. Its presence in French Oligocene sites is thus unproven and we regard it as unlikely. A specimen identified as Bibio cf. fusiformis and illustrated by Théobald (1937, Pl. XXI, Fig. 10) in FSL (FSL 391917) fits the specimens from Öhningen reasonably well but is not well enough preserved for a certain identification. Another specimen (BMNH In 39823) in BMNH is also in too poor condition to identify the species with any degree of certainty. Furthermore, there are four female specimens in MNHM (labeled with the numbers 209-212) identified as Bibio fusiformis. These share with the type specimens the conspicuously slender, cylindrical abdomen but are otherwise devoid of systematically useful characters. , 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, 1000, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1019, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1026, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1029, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1030, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1116, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1144, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1166, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1419, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1742, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , P91, P188, P254, P353, P452, P516, P526, P539. 36 females: Céreste 54, 68, 76, 275, 568, 639, 641, 653, 654, 655, 656, 667, 1011, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1018, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1020, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1021, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1027, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1028, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1099, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1100, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1111, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1134, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1360, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1574, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1655, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1672, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1685, 74, 87, 90, 223, 269, 316, 338, 353, 554, 644, 649, 660, 664, 665, 666, 718, 896, 991, 992, 993, 995, , 1697, P316, P358, P418, P461, P519, P534, P543, P551.

Localities: Corent, Céreste

Diagnosis: a medium-sized to large (8.5-13 mm) Bibio species. Head conspicuously small, width in male about half of thorax width, flagellum slender and 10-segmented. Wing hyaline, vein Rs dips toward M so that crossvein R-M is obliterated, but the two veins are not fused for any distance like in the genus Bibiodes. Pterostigma small, dark and distinctive. Male legs entirely dark, fore tibia with spur approximately half as long as anterior spine, hind femur thick and spindle-shaped, hind tibia rather slender, not clavate, apically truncate. Male epandrium small and not bilobate. Female body dark, legs mostly pale-coloured.

Redescription:

Male (figs. 190-191): Total length 8. Thorax: Length 2.4-3.4 mm (N=20), width 2.0-2.8 mm (N=5). Black. Haltere pale brownish.

Wing (fig. 188): length 6.2-8.0 mm (N=9), width 2.7-3.4 mm (N=5), length/width = 2.12-2.60 (N=5), hyaline, R-veins brown, posterior veins colourless. Pterostigma small, dark and distinctive. Wing vein measurements in Table 4. : Black. Mid-and hind femorae moderately clavate, hind tibia rather slender, straight-sided, apically truncate. Hind first tarsomere slender to moderately robust. Fore femur length 1.4-2.0 mm (N=5), width 0.53-0.65 mm (N=5), fore tibia length 1.5-1.6 mm (N=5), fore first tarsomere length 0.9-1.4 mm (N=4), hind femur length 2.3-3.5 mm (N=20), width 0.51-0.65 mm (N=13), hind tibia length 2.3-3.1 mm (N=22), width 0.34-0.55 mm (N=14), hind first tarsomere length 0.81-0.93 mm (N=6).

Abdomen: Length 5.2-7.1 mm (N=10), width 1.2-1.6 mm (N=8). Black.

Terminalia (fig. 196): Hypopygium width 0.85-1.06 mm (N=8). Epandrium rather small, posteriorly concave but not bilobate, posterior corners slightly protruding. Gonostyli robust, quite long, of the typical shape for genus.

Female (fig. 192): Total length 10.0-13.0 mm (N=12).

Head: Length 1.03-1.30 mm (N=7), width 1.13-1.43 mm (N=7), quite short and broad. Flagellum 10segmented, length 0.67-0.84 mm (N=5).

Thorax: Length 3.2-4.5 mm (N=11), width 2.4-3.2 mm (N=5).

Wing (fig. 189): Length 7.9-10.5 mm (N=6), width 2.9-3.7 mm (N=4), length/width = 2.42-2.71 (N=4). Hyaline, venation as in male. Pterostigma small and dark, distinctive. Wing vein measurements in Table 4.

Legs: Legs mostly pale. Fore femur 2.1-2.4 mm long (N=2), 0.76-0.79 mm wide (N=2), fore tibia 2.1-2.3 mm long (N=3), fore first tarsomere 1.5 mm (N=1), hind femur 2.9-3.6 mm long (N=4), 0.61-0.70 mm wide (N=5), hind tibia 3.1-3.6 mm long (N=6), 0.40-0.49 mm wide (N=4), hind first tarsomere 1.0-1.2 mm (N=3).

Abdomen: Length 6.0-8.6 mm (N=11), width 2.1-3.1 mm (N=7).

Terminalia (fig. 197): Last sternite with a narrow and shallow indetation.

The wing venation of this species approaches the typical venation of the genus Bibiodes Coquillett, which, though only found in the Nearctic region in the recent fauna, is known from several European fossils [START_REF] Skartveit | Fossil Bibionoidea (Diptera: Hesperinidae and Bibionidae) from Baltic amber[END_REF]. Unfortunately, in most of the specimens from Céreste and Aix-en-Provence the wing venation is not visible. But the male genitalia are typical of the genus Bibio and Rs and M just meet without really merging, hence it is classified as a Bibio species.

Bibio moestus Heer, 1849

This species was described from Öhningen, Southern Germany and redescribed by [START_REF] Skartveit | Revision of Bibionidae (Diptera) named by Oswald Heer from the Miocene of Öhningen, Southern Germany[END_REF]. It was recorded from Aix-en-Provence by Heer (1856: 33-34), one specimen is in ETHZ [START_REF] Skartveit | Revision of Bibionidae (Diptera) named by Oswald Heer from the Miocene of Öhningen, Southern Germany[END_REF] , 10, 11, 107, 161, 309, 845, 1090, 1299, 1307, 1446, 1447, P25).

Localities: Aix-en-Provence

Diagnosis: A medium-sized to large (8.5-12 mm), robust Bibio species. The wing has a short but distinctive R-M crossvein, about one fifth as long as basal part of Rs, and CuA1 and CuA2 are apically straight or nearly so. Antenna robust with 8-segmented flagellum. Male epandrium not bilobate, apically straight with slightly protruding posterior corners.

Redescription:

Male (tentatively associated, fig. 200): Total length 9.0-10.0 mm (N=3).

Head (fig. 201): Length 1.3-1.6 mm (N=2), width 1.5 mm (N=1). Dark brown, presumably black in life. Antennal flagellum 8-segmented. Palp relatively short and robust. Ocellar triangle large and prominent.

Thorax: Length 2.8-3.1 mm (N=2), width 2.3 mm (N=1). Dark brown, presumably black in life.

Haltere pale.

Wing (fig. 199): Length 5.8-6.9 mm (N=3), width 2.5-2.8 mm (N=3), length/width = 2.31-2.73 (N=3). Hyaline? Membrane pigmentation not well preserved, veins distinctive throughout. R4+5 arched forwards, running more or less parallel to Costa in distal half. Crossvein R-M short but distinctive. CuA-veins apically straight or nearly so. Wing vein measurements in Table 4.

Legs (fig. 202): Fore tibia with spur a little less than half as long as anterior spine. Hind femur stout, clavate. Hind tibia rather short and robust with long, curved, apically blunt spur. Hind tarsus robust, first tarsomere approximately three times as long as wide. Hind femur length 2.5-2.7 mm (N=3), width 0.52-0.60 mm (N=3), hind tibia length 2.3-2.9 mm (N=3), width 0.40-0.44 mm (N=3).

Abdomen: Length 5.8-6.2 mm (N=3), width 1.3 mm (N=1). Dark brown, presumably black in life, conical.

Terminalia (fig. 203): Hypopygium width 0.92-1.10 mm (N=2). Epandrium not bilobate, posterior margin nearly straight with rounded, slightly protruding posterior corners. Gonostylus large and robust.

Female: Total length 9.3-12.0 mm (N=13)

Head (fig. 204): Length 1.19-1.39 mm (N=6), width 0.93-1.32 mm (N=6). Black. Antennal flagellum 0.55-0.62 mm long (N=2), 8-segmented. Ocellar tubercle small and low. Palp short and robust. Complex eye rather small, about one third length of head.

Thorax: Length 2.8-3.8 mm (N=13), width 2.1-3.1 mm (N=5). Haltere dark brown.

Wing (fig. 198): Length 6.7-10.6 mm (N=14), width 3.0-4.3 mm (N=14), length/width = 2.08-2.62 (N=14). Grayish hyaline, pterostigma oval, dark brown, wing mesally with a chocolate-brown band stretching from the origin of Rs distad to pterostigma, posteriorly to CuA1.Crossvein R-M short but distinctive, about one fifth as long as basal section of Rs. The CuA-veins apically straight or nearly so.

Wing vein measurements in Table 4.

Legs (fig. 205): femorae and tibiae brownish yellow, tibiae apically darker. Fore femur relatively slender, about three times as long as wide in lateral view. Fore tibia with spur about one third the length of anterior spine. All tarsi slender, tarsomeres brownish yellow, apically darkened. Hind femur slightly clavate, hind tibia slender. Metatibial spur rather long, blunt. Fore femur length 1.8-2.4 mm (N=9), width 0.69-0.86 mm (N=7), fore tibia length 1.7-2.4 mm (N=11), width 0.46-0.47 mm (N=2), hind femur length 2.6-3.6 mm (N=11), width 0.54-0.76 mm (N=9), hind tibia length 2.7-3.9 mm (N=11), hind first tarsomere 1.0-1.2 mm (N=5).

Abdomen: Length 6.1-9.2 mm (N=15), width 2.5-2.8 mm (N=6). Blackish brown.

Terminalia (fig. 206): Cercus slender, rounded. It may appear to have two segments but this is probably an artefact.

There is also a specimen in FSL (FSL 391912) labeled as a paratype of B. spectabilis. This specimen, however, has a slender fore tibia and a distinctive vein R2+3 and belongs in the genus Plecia. In ETHZ there is a female specimen labeled "Bibio spectabilis Heer" (ETHZ Pl. I 855) from the Miocene site of Öhningen. The specimen actually belongs to Bibio moestus [START_REF] Skartveit | Revision of Bibionidae (Diptera) named by Oswald Heer from the Miocene of Öhningen, Southern Germany[END_REF], and the name Bibio spectabilis Heer was apparently never formally published and so does not affect the nomenclature of this species. Using the dark-banded wings as an identification character is problematic since the vast majority of the specimens from Aix-en-Provence have no preserved wing pigmentation. Material examined: Holotype (male) MNHN Aix 1079. The specimen is preserved lying on the side, but with abdomen twisted so that the terminalia can be seen as if from dorsal view. Paratypes: males: MNHN Aix 62, 676. Females: MNHN Aix 23, 543, 959.

Genus

Localities: Aix-en-Provence

Diagnosis: A medium-small (5.5-7.5 mm) bibionid, though relatively large for the genus. Antenna stout, flagellum possibly 5-segmented. Hind tibia strongly clavate. Male gonostyli are simple and digitiform.

Description:

Male: Total length 5.5-7.0 mm (N=3). The specimens have head and thorax brown, legs and abdomen pale brown, no pigmentation preserved in wings.

Head (fig. 208): Length 0.97-1.24 mm (N=3). Ocellar triangle tall and prominent. Complex eye without conspicuous pile, lower section prominent. Antenna stout, flagellum possibly 5-segmented, 0.63 mm long (N=1).

Thorax: Length 2.0-2.8 mm (N=3). Brown.

Wing: Length 4.3-5.8 mm (N=3), width 1.7-2.5 mm (N=2), length/width = 2.37-2.50 (N=2)). Apparently hyaline. Few details discernible in specimen at hand. Wing vein measurements in Table 5.

Legs: Protibia with long spine. Hind femur and tibia strongly clavate. Hind tarsus swollen. Length of fore tibia 1.2-1.5 mm (N=2), fore first tarsomere 0.9 mm (N=1), hind femur 1.6-2.5 mm (N=3), width 0.31-0.50 mm (N=3), hind tibia 1.5-2.4 mm (N=3), width 0.37-0.50 mm (N=3), hind first tarsomere 0.7 mm (N=1).

Abdomen: Length 3.8-4.0 mm (N=3). Pale brown.

Terminalia (fig. 211): Hypopygium width 0.57-0.86 mm (N=2). Epandrium bilobate, lobes rounded, indentation between them widely U-shaped. Gonostylus length 0.31 mm (N=1), digitiform.

Female (fig. 209): Total length 6.0-7.5 mm (N=3). All specimens are preserved as relief impressions with little or no preserved colouration.

Head: Length 0.81-0.83 mm (N=1), width 0.81-0.93 mm (N=2). Relatively short and broad. Ocellar triangle prominent. Complex eye rounded, length approximately half length of head. Antenna stout, flagellum 0.5 mm long (N=1), possibly 5-segmented.

Thorax: Brown. Length 1.8-2.5 mm (N=3), width 1.9 mm (N=1).

Wing (fig. 207): Length 5.2-6.5 mm (N=3), width 2.0-2.7 mm (N=3), length/width = 2.11-2.64 (N=3). Veins fine, Costa extends slightly beyond apex of R4+5. Veins Rs and M are merged for a distance about twice the length of basal section of Rs. Pterostigma not apparent. Wing vein measurements in Table 5.

Legs (fig. 210): Protibia with ventral tubercle and long spine. Hind tibia clavate, hind tarsus swollen. Fore femur length 1.3-1.6 mm (N=2), width 0.4-0.7 mm (N=2). Fore tibia length 1.2-1.8 mm (N=2). Hind femur length 1.7-2.3 mm (N=2), width 0.37-0.49 mm (N=2), hind tibia length 1.6-2.1 mm (N=2), width 0.29-0.39 mm (N=2). Hind first tarsomere 0.5-0.8 mm (N=2).

Abdomen: Cylindrical. Length 3.9-4.7 mm (N=3), width 1.8-2.1 mm (N=2).

Terminalia: Not clearly visible in any of the specimens at hand.

Bibiodes sp. (Fig. 212)

This species is represented by a single female specimen.

Material: NMB F2136 (1 female)

Localities: Kleinkembs

Diagnosis:

The single female specimen is not well enough preserved to be reliably separated from B. provincialis, but the antenna appears to be more slender, and the section where veins Rs and M are fused appears to be shorter than in B. provincialis.

Description:

Male unknown Female: Total length 6.5 mm (N=1).

Head: Length 0.7 mm (N=1). Black. Complex eye relatively small. Ocellar tubercle tall and prominent. Antenna not well preserved but appears to be relatively slender.

Thorax: Length 2.2 mm (N=1). Black. Scutum strongly developed, relatively flat. Haltere dark reddish brown.

Wing: Length 6.0 mm, width 2.1 mm, length/width = 2.92 (N=1). Hyaline, veins yellowish, pterostigma oval, light brown, distinctive. Costa extends slightly beyond apex of R4+5. Subcosta fine and indistinctive, humeral vein probably present. Radial sector and M merged for a short distance. M and CuA with relatively short stems and long forks. Wing vein measurements in Table 5.

Legs: Blackish-brown, presumably black in life, robust. Fore femur length 1.4 mm, width 0.62 mm, fore tibia length 1.5 mm, with short, stout spur, less than one third as long as spine. Hind femur length 1.9 mm, width 0.44 mm, stout throughout, hind tibia length 2.0 mm, width 0.27 mm, slender, first tarsomere slender.

Abdomen: Chestnut-brown, rather stout, cylindrical. Length 3.8 mm (N=1).

Terminalia: The tergites of the last three segments are apparently missing, so the internal structures are uncovered. Genital fork and two spermathecae are clearly visible, but a third spermatheca may be partly hidden. Localities: Aix-en-Provence.

Genus

Diagnosis: A medium-sized Dilophus, 5.5-6.0 mm. Mesonotum black, pleurae yellowish, legs yellowish-brown with black tarsi. Protibia possibly with three mesal spines. Wing hyaline with small, dark brown pterostigma.

Redescription:

Male unknown. There are several male Dilophus specimens from Aix-en-Provence in MNHN, but it is highly uncertain if these belong to D. luteipennis.

Female: Total length 5.5-6.0 mm (N=2).

Head (fig. 214): Length 0.7 mm (N=1). Black. Antenna short and stocky, segments not possible to count in the specimens at hand.

Thorax: Length 1.3-1.5 mm (N=2), width 1.4 mm (N=1). Mesonotum black, pleura brownish-yellow. Spine rows not possible to see in the specimens at hand.

Wing (fig. 213): Length 4.0-4.6 mm (N=2), width 1.5-1.8 mm (N=2). Hyaline, pterostigma small, oval and dark brown, R-veins dark brown, posterior veins colourless. Costa extends to apex of R4+5.Crossvein R-M slightly longer then basal part of Rs. Wing vein measurements in Table 5.

Legs: Yellowish-brown, tarsi black. Protibia rather stout, possibly with three mesal spines. Hind femur 1.3 mm, hind tibia 1.2 mm (N=1).

Abdomen: Length 3.7-4.4 mm (N=2), width 1.5 mm (N=1). Cylindrical, dark brown.

Terminalia: Cerci rather long, apically blunt, slightly hooked.

Further Dilophus specimens

Specimens belonging to the genus Dilophus are scarce but present from many of the localities.

Unfortunately, important diagnostic features such as the shape of male terminalia, antennae and protibiae are rarely preserved, thus it is not advisable to describe new species based on this material.

The genus has been noted from the following localities:

Céreste: EEFN F 312 (male, 6.7 mm). This specimen was listed by Théobald (1937: 404) as Bibio detractus. Chadrat: MNHN Chadrat P10 (female, 8 mm). Monteils: MNHN Monteils 148 (male, 4.3 mm), Monteils 159 (female, 8 mm). Bois d'Asson: RGL Bois d'Asson 43 (female, 6.0 mm). Aix-en-Provence: MNHN Aix 18 (female, 10 mm), Aix 31 (male, 5.0 mm), Aix 34 (male, 6.5 mm), Aix 491 (male, thorax length 1.2 mm), Aix 797 (male, 6.2 mm), Aix 1079 (male, 5.5 mm). Kleinkembs: NMB F2110 (male, 5.5 mm), F2246 (male, 5.5 mm).

Unrecognizable species

A number of species described from French Oligocene deposits is based on material which is too poorly preserved to be recognizable at the species level. We have examined the types of the following and they should be reclassified as follows:

Bibio disjectus Théobald, 1937: 334. Nomen dubium. Holotype: FSL 391916. The type specimen is a male specimen, 8.5 mm long. It is possibly the same as Bibio major, but since neither head, legs nor wings are well preserved in the type specimen, the species cannot be recognized.

Plecia larteti [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 137 [Bibio]. Nomen dubium. Holotype: MNHN R 06667. Female specimen, total length 6.7 mm. The specimen is too poorly preserved to be recognizable at the species level, but the wing venation reveals it is a Plecia. Plecia painvini (Meunier, 1915): 16. [Bibio]. Nomen dubium. Probable holotype: EM 70000, temporarily stored in FSL. The specimen fits the photo of the holotype given in Meunier's paper (Fig. 18) and also fits the measurements given by Meunier perfectly. It is a poorly preserved Plecia female. Oustalet, 1870: 115. Nomen dubium. Syntypes: MNHN R 06691 and R 06694. Two male specimens. Wings and legs are missing in both specimens, hypopygium not visible. It is hard to ascertain what these specimens really are, they belong to Nematocera but we are not able to classify them further.

Plecia nigrescens

Plecia retracta Théobald, 1937: 341-342 Plecia joannis [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 143. [Protomyia]. Nomen dubium. Holotype: MNHN R 06690. Female specimen, approx. 8 mm long, very weak impression. A short R2+3 shows it to be a Plecia, but otherwise unrecognizable.

Plecia longipennis [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 141. [Protomyia]. Nomen dubium. Holotype: MNHN R 06673. Female specimen, total length 6.1 mm. [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 149. [Protomyia]. Nomen dubium. Holotype: MNHN R 07026. Female specimen, approx. 8 mm long. The specimen is bright rusty-red due to impregnation with iron. It is a Plecia but is not further recognizable.

Plecia rubescens

Plecia sauvagei [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 146. [Protomyia]. Nomen dubium. Holotype: MNHN R 06680. A rather large Plecia female, total length 9.6 mm. Not recognizable.

Species for which we have not found type material

Judging from the original descriptions and the accompanying drawings, probably none of these species described by [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF] are recognizable at the species level, though for most it is possible to place them tentatively to genus. All these names should be considered nomina dubia unless the type specimens are found at some time in the future. Oustalet, 1870: 112-113. The species was drawn with an unbranched R4+5 (Oustalet 1870 Pl. 3, Figs. 1-2). Penthetria specimens with unbranched R4+5 are known [START_REF] Skartveit | Fossil Bibionoidea (Diptera: Hesperinidae and Bibionidae) from Baltic amber[END_REF], but this is highly un-typical of the genus. It is not clear from Oustalet's drawings if the species belongs in Bibionidae. Identification: Nematocera indet. Plecia angustiventris Théobald, 1937: 135. Holotype supposed to be in Marseille, presumably lost. The photo given by Théobald (1937, Pl. II, Fig. 4) shows a female specimen with a short R2+3. The species belongs in the genus Plecia. Plecia dumasi Théobald, 1937: 138. Holotype supposed to be in Nîmes, presumably lost. The illustration (Théobald 1937, Pl. XI, Fig. 2) accompanying the original description shows a typical female Plecia. Plecia pallida [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 118-119. Oustalet (1870, Pl. 3. Figs. 11-13) depicted three male specimens. No systematically important characters can be seen in the drawings, but the habitus suggests the species is correctly placed in Plecia. Bibio alacris Oustalet, 1870: 127. Oustalet (1870, Pl. 3, Fig. 15) depicted a slender specimens with thin anterior legscertainly not a Bibio species. Judging from the habitus the species probably belongs in genus Penthetria. Bibio cylindratus Oustalet, 1870: 133. Oustalet (1870, Pl. 4, Fig. 12) depicted a bibionid female. The wing venation is not apparent from the drawing, but the habitus suggests it is either Penthetria or Plecia, most likely the latter. Théobald, 1937: 141. Holotype supposed to be in Marseille, presumably lost. The photo (Théobald 1937, Pl. II, Fig. 13) given in the original description shows a slender female specimen which clearly belongs in the genus Penthetria. Bibio gigas Oustalet, 1870: 122. Oustalet (1870, Pl. 4, Figs. 1-4) drew four female specimens, all poorly preserved. Their long, slender bodies suggest it should be placed in genus Penthetria, as does the large size of the specimens. [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 126 (nec Loew, 1871). Oustalet (1870, Pl. 4, Fig. 6) drew a female specimen without wings, but with slender legs. The elongate body shape suggests it belongs in Penthetria. Bibio maceratus Théobald, 1937: 142-143. Holotype supposed to be in Marseille, presumably lost. The illustration given by Théobald (1937, Pl. II, Fig. 12) shows a slender female specimen, probably belonging to the genus Penthetria. Judging from the illustrations there is a very high likelihood that B. elongatipennis and B. maceratus are synonyms. [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 134. Oustalet (1870, Pl. 3, Fig. 16) drew a slender, female specimen. No vein R2+3 was indicated, but the slender habitus and the vertical R-M suggests it belongs in Penthetria. Bibio nigripennis Théobald, 1937: 286, nec Brunetti, 1913. Holotype supposed to be in Marseille, presumably lost. One specimen labeled as this species in MHNM is not the one illustrated by Théobald, and is actually a chironomid. The species name is a primary junior homonym of Bibio nigripennis [START_REF] Brunetti | New and interesting Diptera from the Eastern Himalayas[END_REF] and thus invalid. The illustration (Théobald 1937, Pl. XX, Fig. 5) shows a female specimen which, although no vein R2+3 is apparent, clearly belongs in the genus Plecia. We propose the name Plecia theobaldi nom.n. as a replacement name for this species. [START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 128. Oustalet (1870, Pl. 4, Figs. 7-9) drew three female specimens in poor condition. No vein R2+3 is apparent in the drawings, but the habitus will place the species in genus Plecia or Penthetria, most likely the former.

Penthetria vaillantii

Bibio elongatipennis

Bibio macer

Bibio minor

Bibio robustus

Discussion

Bibionid flies make up a morphologically rather homogenous group and differences between species tend to be slight in the recent fauna. Thus, new species in this group should not be described based on fragmentary fossil material except possibly for species that possess some distinctive and unusual morphological traits. As a minimum, specimens should be available which show the wing venation and the male terminalia (particularly epandrium and gonostyles) and preferably the antennae. In the Bibioninae, fore and hind legs should also be available for study, at least the tibiae which are very useful in this subfamily. The appearance of the genital structures are highly dependent upon the position in which they have been fossilized. Since compression fossils cannot be rotated, this is highly problematical. In the present material we were able to deduce the shape of the male gonostylus because we had access to a very large number of specimens in which this was fixed in various positions. With a smaller number of specimens, it is easy to interpret the various positions as distinctive shapes and classify them as different species.

The majority of named fossil bibionids have been described based on specimens which do not fulfil these requirements, in particular most are based on female specimens, and connecting male and female specimens has rarely been attempted. The synonymies we have suggested are tentative in the sense that it is always possible that two nominal species could be distinguished if perfectly preserved specimens, showing all relevant characters, were available. However, we believe that a conservative approach should be followed in paleontology, whereby sound evidence is needed to justify the treatment of two taxa as different. In the absence of such evidence they should, for simplicity, be regarded as the same. This approach may lead to over-estimates of the longevity of species when sound evidence for distinguishing specimens of different age cannot be found.

Except for the Kleinkembs locality that is situated in the northern part of France, all the studied outcrops are distributed in the relatively narrow area in the Centre and South-East of France. Therefore they are of interest for a study of the evolution of the bibionid faunas (see Fig. xxx,map).

In the present material, a distinctive change in the bibionid faunas during the Oligocene is obvious. The oldest localities at Célas, Monteils and Camoins harbour a distinctive, Early Oligocene fauna including Penthetria graciliventris, Penthetria longiventris and Bibio celasensis. Most of the species found in the locality of Kleinkembs are unique to this site, however there are shared species both with older (Plecia foersteri shared with Célas) and presumably younger (Penthetria lugens, Plecia lapidaria) sites. The most distinctive element of the middle Oligocene sites such as Bois d'Asson, Corent and Céreste are the abundant species Plecia livida and Bibio major, the former however also occur in Aix-en-Provence. The youngest site of Aix-en-Provence has several unique species: Plecia morio, Bibio aquaesextiae, Bibio curtisii, Bibio spectabilis, Bibiodes provincialis and Dilophus luteipennis. At least three of the species found in Aix also occur in the similar-age site of Rott, Germany and one (Plecia lygaeoides) in the younger site of Radoboj, Croatia.

Fossil bibionid flies are potentially useful for the reconstruction of past environments, in particular climate [START_REF] Collomb | March flies and European Cenozoic palaeoclimates (Diptera: Bibionidae)[END_REF]. But if such attempts are to be worthwhile, it is essential that the taxonomy is realistic. The estimates of [START_REF] Collomb | March flies and European Cenozoic palaeoclimates (Diptera: Bibionidae)[END_REF] were based on the frequencies of different bibionid genera (based on recently collected material), which makes sense since the modern bibionid genera have to a large extent different climate requirements. In working with the present revision we have found that a large fraction of the nominal species have been placed in the wrong genus, which will compromise the use of the ancient described species to make inferences about past climates. On the other hand, a realistic classification of fossil bibionids may open new opportunities to use these abundant fossils in the study of past environments. At present, the somewhat ambiguous delimititation of the genera Penthetria and Plecia causes problems for climate reconstructions since these two genera have different climate preferences. [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF]. Figs. 95-97. Penthetria lugens (Oustalet, 1870) Fig. 95. Female, wing. NMB F2410. Fig. 96. Female, head and thorax, dorsal. FSL 391923. Fig. 97. Female, terminalia, ventral. NMB F2413. Figs. 98-92. Penthetria nervisinuata [START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF] Fig. 112. Female, head and thorax, lateral. ETHZ Aix 142. Fig. 113. Female, head and thorax, dorsal. NHMUK In 39832. Figs. 114-118. Plecia conica Théobald, 1937. Fig. 114. Male, wing. NMB F2090. Fig. 115. Male, habitus, lateral. RGL Dauphín 12. Fig. 116. Male, habitus, dorsal. RGL Saint Maime 23'. Fig. 117. Male, terminalia, dorsal. RGL Dauphín 12. Fig. 118. Male, terminalia, lateral. NMB F1398/2. Figs. 119-122. Plecia foersteri Théobald, 1937Fig. 119. Female, wing. NMB F1411/22. Fig. 120. Female, head and thorax, dorsal. NMB F2423. Fig. 121. Female, terminalia, ventral. NMB F1411/13. Fig. 122. Female, head and thorax, NMB F1390. Figs. 123-125. Plecia inflata Oustalet, 1870Fig. 123. Female, wing. NMB F2345. Fig. 124. Female, head and thorax, lateral. NMB F2215. Fig. 125. Female, terminalia, dorsal. NMB F2344. Figs. 126-128. Plecia lapidaria Heyden & Heyden, 1865Fig. 126. Female, wing. NHMUK In 58813. Fig. 127. Female, head and thorax. NMB F1530. Fig. 128. Female, terminalia. NMB F1565. Figs. 129-131. Plecia larguensis Gentilini, 1993 Fig. 129. Male, wing. RGL Bois d'Asson 7. Fig. 142. Female,terminalia,ventral,RGL Céreste 499. Fig. 143. Female,terminalia,dorsal,. Plecia lygaeoides [START_REF] Heer | Die Insektenfauna der Tertiärgebilde von Oeningen und von Radoboj in Croatien. Zweite Abtheilung: Heuschrecken, Florfliegen, Aderflügler, Schmetterlinge und Fliegen[END_REF]) Fig. 144. Female, wing. FSL 391929. Fig. 145. Male, head, NHMUK In 58805. Fig. 146. Female, head. ETHZ. Fig. 147. Male, terminalia, ventral. RGL Céreste 522. Fig. 148. Male, terminalia, dorsal. FSL 391921. Figs. 149-153. Plecia maimensis Gentilini, 1993 Fig. 149. Male, wing. RGL Dauphín 1. Fig. 150. Male, habitus. RGL Dauphín 122. Fig. 151. Female, habitus. RGL Bois d'Asson 4. Fig. 152. Male, terminalia, dorsal. RGL Bois d'Asson 24. Fig. 153. Female, terminalia, dorsal. RGL Bois d'Asson 4. Figs. 154-159. Plecia morio [START_REF] Heer | Die Insektenfauna der Tertiärgebilde von Oeningen und von Radoboj in Croatien. Zweite Abtheilung: Heuschrecken, Florfliegen, Aderflügler, Schmetterlinge und Fliegen[END_REF] Figs. 184-187. Bibio dislocatus Théobald, 1937Fig. 184. Female, wing. NMB F1385/3. Fig. 185. Female, habitus. NMB F1383. Fig. 186. Female, head and thorax. NMB F1386/2. Fig. 187. Female, terminalia, ventral. NMB F1385/4. Figs. 188-197. Bibio major (Oustalet, 1870) Fig. 192. Female, habitus. MNHN Aix 1286. Fig. 193. Male, head. MNHN Aix 313. Fig. 194. Male, fore leg. MNHN Aix 313. Fig. 195. Male, hind leg. MNHN Aix 89. Fig. 196. Male, terminalia, dorsal. RGL Céreste 34. Fig. 197. Female, terminalia, ventral. MNHN Aix 2. Fig. 198-206. Bibio spectabilis Théobald, 1937 Fig. 198. Female, wing. FSL 391911. Fig. 199. Male, wing. MNHN Aix 1436. (Théobald, 1937) Fig. 213. Female, wing. FSL 391913. Fig. 214. Female, head and thorax. FSL 391913.

Legends to figures

  Material examined: Holotype, female, FSL 391925 (fig. 14) from Aix. Paratype, female, FSL 391926. Paratype, female, MNHN B 24519 from Céreste. Female, attributed by Heer to Bibiopsis funebris Heer (ETHZ 164).

Bibiodes Coquillett, 1904

 1904 Bibiodes provincialis sp.n. (figs. 69-70, 207-211)

  Holotype (female) of Bibio luteipennis FSL 391913 (A 16). Paratype (female) of Bibio luteipennis FSL 391914 (A 86).

Fig. 1 .

 1 Fig. 1. Penthetria claripennis, female. Holotype of Plecia claripennis Théobald, NMB F1382.

Fig. 2 .

 2 Fig. 2. Penthetria claripennis, male. Holotype of Plecia variegata Théobald, NMB F1405.

Fig. 3 .

 3 Fig. 3. Pentehtria claripennis, male. Holotype of Plecia varia Théobald, NMB F1407.

Fig. 4 .

 4 Fig. 4. Penthetria claripennis, male. Holotype of Plecia difficilis Théobald, NMB F1408.

Fig. 5 .

 5 Fig. 5. Penthetria claripennis, male. Holotype of Plecia graciosa Théobald, NMB F1409.

Fig. 6 .

 6 Fig. 6. Penthetria gigantea, female. Holotype of Plecia gigantea Théobald, NMB F1380.

Fig. 7 .

 7 Fig. 7. Penthetria gigantea, female. Holotype of Plecia crassiventris Théobald, NMB F1381.

Fig. 8 .

 8 Fig. 8. Penthetria gigantea, male. Holotype of Plecia miegi Théobald, NMB F1399.

Fig. 9 .

 9 Fig. 9. Penthetria gigantea, male. Holotype of Plecia luteipennis Théobald, NMB F1402.

Fig. 10 .

 10 Fig. 10. Penthetria graciliventris. MNHN Monteils 35.

Fig. 11 .

 11 Fig. 11. Penthetria longiventris, female. Paratype of Plecia superba Théobald, FSL 391901.

Fig. 12 .

 12 Fig. 12. Penthetria luberonica, male. Holotype of Penthetria luberonica sp.n., ECL 140.048/2.

Fig. 13 .

 13 Fig. 13. Penthetria luberonica, female. ECL 140.046.

Fig. 14 .

 14 Fig. 14. Penthetria lugens, female. Holotype of Protomyia lugens Oustalet, MNHN R 06666.

Fig. 15 .

 15 Fig. 15. Penthetria lugens, female. NMB F2410.Fig. 16. Penthetria nervisinuata, female. Holotype of Plecia nervisinuata Théobald, FSL 391925.

Fig. 17 .

 17 Fig. 17. Penthetria nervisinuata, female. ETHZ, labeled 164.

Fig. 18 .

 18 Fig. 18. Penthetria subterranea, male. Holotype of Plecia subterranea Théobald, NMB F1404.

Fig. 19 .

 19 Fig. 19. Plecia assonensis, male. MNHN Bois d'Asson 81.

Fig. 20 .

 20 Fig. 20. Plecia bucklandi, female. Specimen identified as Protomyia bucklandi Heer by Heer, ETHZ, no specimen number.

Fig. 21 .

 21 Fig. 21. Plecia bucklandi, female. Syntype of Protomyia elegans Heer, NHMUK In 39832. Image reproduced with permission from NHMUK.

Fig. 22 .

 22 Fig. 22. Plecia bucklandi, female. Syntype of Protomyia gracilis Heer, NHMUK In 38765. Image reproduced with permission from NHMUK.

Fig. 23 .

 23 Fig. 23. Plecia bucklandi, female. Syntype of Bibio edwardsii Oustalet, MNHN R 06671.

Fig. 24 .

 24 Fig. 24. Plecia bucklandi, female. Holotype of Plecia dilatativentris Théobald, FSL 391924. Fig. 25. Plecia foersteri, female. Holotype of Plecia försteri Théobald, NMB F1390 Fig. 26. Plecia foersteri, female. Holotype of Plecia splendida Théobald, NMB F1396.

Fig. 27 .

 27 Fig. 27. Plecia foersteri, female. Holotype of Plecia oviformis Théobald, NMB F1384. Fig. 28. Plecia foersteri, female. "Hypotypoide" of Plecia rubescens (Oustalet) sensu Théobald, NMB F1395/1. Fig. 29. Plecia conica, male. Holotype of Plecia conica Théobald, NMB F1398.

Fig. 30 .

 30 Fig. 30. Plecia conica, male. MNHN Dauphín 12.

Fig. 31 .

 31 Fig. 31. Plecia inflata, female. Holotype of Plecia inflata Oustalet, NMB F1495.

Fig. 32 .

 32 Fig. 32. Plecia lapidaria, female. Syntype of Plecia lapidaria Heyden & Heyden, NHMUK In 58813. Image reproduced with permission from NHMUK.

Fig. 33 .

 33 Fig. 33. Plecia lapidaria, female. NMB F2406.

Fig. 35 .

 35 Fig. 35. Plecia larguensis, male. RGL Dauphín 30.

Fig. 36 .

 36 Fig. 36. Plecia livida, female. Lectotype of Protomyia livida Heer, NHMUK In 39854. Image reproduced with permission from NHMUK.

Fig. 37 .

 37 Fig. 37. Plecia livida, male. Syntype of Protomyia brevipennis Heer, NHMUK In 39830. Image reproduced with permission from NHMUK.

Fig. 38 .

 38 Fig. 38. Plecia livida, male. Holotype of Plecia acutiventris Théobald, MNHN Ex. 169.

Fig. 39 .

 39 Fig. 39. Plecia livida, female. Holotype of Plecia goreti Théobald, MNHN B 24516.

Fig. 40 .

 40 Fig. 40. Plecia livida, female. Paratype of Plecia guineri Théobald, MNHN B 24415.

Fig. 41 .

 41 Fig. 41. Plecia livida, male. Holotype of Plecia maculiventris Théobald, MNHN B 24523.

Fig. 42 .

 42 Fig. 42. Plecia lygaeoides, female. Holotype of Protomyia lygaeoides Heer, SLJG 77465.

Fig. 43 .

 43 Fig. 43. Plecia lygaeoides, male. Holotype of Protomyia gracilenta Heer, BMNH In 58805. Image reproduced with permission from BMNH.

Fig. 44 .

 44 Fig. 44. Plecia lygaeoides, male. Holotype of Bibio detractus Théobald, FSL 391921.

Fig. 45 .

 45 Fig. 45. Plecia maimensis, male. RGL Dauphín 122.

Fig. 46 .

 46 Fig. 46. Plecia maimensis, female. RGL Bois d'Asson 4.

Fig. 47 .

 47 Fig. 47. Plecia morio, female. NHMUK In 39831. Image reproduced with permission from NHMUK.

Fig. 48 .

 48 Fig. 48. Plecia morio, female. Syntype of Protomyia collossea Heyden & Heyden, NMHUK In 58789. Image reproduced with permission from NHMUK.

Fig. 49 .

 49 Fig. 49. Plecia rhenana, female. Syntype of Plecia rhenana Heyden & Heyden, NHMUK In 38798. Image reproduced with permission from NHMUK.

Fig. 50 .

 50 Fig. 50. Bibio aquaesextiae, male. Holotype of Bibio aquaesextiae sp.n., MNHN Aix 152.

Fig. 51 .

 51 Fig. 51. Bibio baumbergeri, female. Holotype of Bibio baumbergeri Théobald, NMB F456.

Fig. 52 .

 52 Fig. 52. Bibio baumbergeri, female. Holotype of Bibio parenti Théobald, NMB F1372. Fig. 53. Bibio celasensis, male. Male specimen from syntype slab, MHNM.

Fig. 54 .

 54 Fig. 54. Bibio celasensis, female. Female specimen from syntype slab, MHNM.

Fig. 55 .

 55 Fig. 55. Bibio celasensis, female. Syntype of Bibio conformans Théobald, FSL 392012.

Fig. 56 .

 56 Fig. 56. Bibio curtisii, male. Lectotype of Bibio curtisii Heer, NHMUK In 39833. Image reproduced with permission from NHMUK.

Fig. 57 .

 57 Fig. 57. Bibio curtisii, male. Counterpart of lectotype, NHMUK In 39855. Image reproduced with permission from NHMUK.

Fig. 58 .

 58 Fig. 58. Bibio curtisii, female. Possible type of Bibio martinsi Heer, ETHZ S.N. 131.

Fig. 59 .

 59 Fig. 59. Bibio curtisii, female. Holotype of Bibio romani Théobald, FSL 391915.

Fig. 60 .

 60 Fig. 60. Bibio curtisii, female. Paratype of Bibio serresi Théobald, FSL 391905.

Fig. 61 .

 61 Fig. 61. Bibio curtisii, sex uncertain. Specimen identified as Bibio bimaculatus (Heer? Status uncertain), ETHZ 137.

Fig. 62 .

 62 Fig. 62. Bibio dislocatus, female. Holotype of Bibio dislocatus Théobald, NMB F1378.

Fig. 63 .

 63 Fig. 63. Bibio dislocatus, female. Holotype of Bibio consolida Théobald, NMB F1379.

Fig. 64 .

 64 Fig. 64. Bibio dislocatus, female. Holotype of Plecia macroventris Théobald, NMB F1383.

Fig. 65 .

 65 Fig. 65. Bibio major, male. Syntype of Plecia major Oustalet, MNHN R 06693.

Fig. 66 .

 66 Fig. 66. Bibio major, female. Syntype of Bibio ungeri marginatus, MNHN R 07253.

Fig. 67 .

 67 Fig. 67. Bibio major, male. RGL Céreste 316.

Fig. 68 .

 68 Fig. 68. Bibio spectabilis, female. Holotype of Bibio spectabilis Théobald, FSL 391911.

Fig. 69 .

 69 Fig. 69. Bibiodes provincialis, male. Holotype of Bibiodes provincialis sp.n., MNHN Aix 1079.

Fig. 70 .

 70 Fig. 70. Bibiodes provincialis, female. MNHN Aix 959.

Fig. 71 .

 71 Fig. 71. Dilophus luteipennis, female. Holotype of Bibio luteipennis Théobald, FSL 391913.

Fig. 72 .

 72 Figs. 72-77 Penthetria claripennis[START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF]. Fig. 72. Male, wing. NMB F1416/1. Fig. 73. Male, terminalia, ventral. NMB F1416/3. Fig. 74. Male, terminalia, dorsal. NMB F1416/6. Fig. 75. Male, terminalia, lateral. NMB F1419/4. Fig. 76. Female, wing. NMB F1382. Fig. 77. Male, habitus: NMB F1418/1.

Fig. 98 .

 98 Fig. 98. Female, wing. ETHZ Aix 164. Fig. 99. Female, head and thorax, dorsal. ETHZ Aix 164. Fig. 100. Female (?), wing, RGL Céreste 192. Fig. 101. Male, terminalia, dorsal. MNHN Aix 981. Fig. 102. Male, wing. MNHN Aix 974.

Fig. 130 .

 130 Figs. 129-131. Plecia larguensis Gentilini, 1993 Fig. 129. Male, wing. RGL Bois d'Asson 7. Fig. 130. Male, head and thorax. RGL Bois d'Asson 7. Fig. 131. Male, terminalia, dorsal. RGL Dauphín 182.

Fig. 154 .

 154 Fig. 154. Male, wing. MNHN Aix 1398. Fig. 155. Female, wing. NHMUK In 39860. Fig. 156. Male, head and thorax, dorsal. MNHN Aix 885. Fig. 157. Male, head and thorax, ventral. MNHN Aix 1398. Fig. 158. Female, head. NHMUK In 39831. Fig. 159. Female, head and thorax. NHMUK In 39860.

Fig. 188 .

 188 Figs. 188-197. Bibio major (Oustalet, 1870) Fig. 188. Male, wing. MNHN Aix Am 67. Fig. 189. Female, wing. RGL Céreste 655. Fig. 190. Male, habitus. MNHN Aix 313. Fig. 191. Male, habitus. RGL Céreste 1029. Fig. 192. Female, habitus. MNHN Aix 1286. Fig. 193. Male, head. MNHN Aix 313. Fig. 194. Male, fore leg. MNHN Aix 313. Fig. 195. Male, hind leg. MNHN Aix 89.Fig. 196. Male, terminalia, dorsal. RGL Céreste 34. Fig. 197. Female, terminalia, ventral. MNHN Aix 2.

Fig. 200 .

 200 Fig. 198-206. Bibio spectabilis Théobald, 1937 Fig. 198. Female, wing. FSL 391911. Fig. 199. Male, wing. MNHN Aix 1436. Fig. 200. Male, habitus. MNHN Aix 313. Fig. 201. Male, head and thorax. MNHN Aix 1436. Fig. 202. Male, hind leg. MNHN Aix 1377. Fig. 203. Male, terminalia. MNHN Aix 1436. Fig. 204. Female, head and thorax. MNHN Aix 1299. Fig. 205. Female, hind leg. MNHN Aix 845. Fig. 206. Female, terminalia. MNHN Aix 845.

Fig. 212 .

 212 Fig. 212. Bibiodes sp., female, habitus. NMB F2136.

  Wing veins not black throughout, pterostigma indistinctive. R2+3 curved.

		Plecia bucklandi
	12. Male gonostylus hooked and sharply pointed, epandrium with three finger-like projections.
	Female unknown.	Plecia larguensis
	Male gonostylus not hooked and pointed, or male unknown	-13
	13. Slender species, legs and abdomen pale brown.	-14
	Rbust species, legs and abdomen dark brown.	-18
	14. Wing narrow, hyaline, R-veins brown, very distinctive. Larger species, wing length 9mm.
	Flagellum 9-segmented.	Plecia rhenana
		Plecia inflata
	Smaller species, body length less than 8 mm, female sternite VIII without hook-shaped
	appendage	-19
	19. Wing with pterostigma conspicuous, R2+3 distinctly curved.	Plecia lapidaria
	Wing with pterostigma inconspicuous, R2+3 nearly straight.	Plecia foersteri
	20. Fore tibia cylindrical with mesal spines, crossvein R-M longer than basal Radial sector.
	Smaller species, body length 5.5-6 mm.	Dilophus luteipennis
	Fore tibia spindle-shaped with apical spine, R-M shorter than basal Radial sector. Mostly larger
	species.	-21

5 mm. Female head not conspicuously small. -11 11. Wing veins black throughout, pterostigma black and distinctive. R2+3 straight, may have a kink in middle part. Plecia lygaeoides Wing wider, R-veins not darker than more posterior veins. Mostly smaller species. Flagellum often with fewer than 9 segments. -15 15. Larger species, male wing length at least 5.8 mm. Male gonostylus not sharply pointed, apically thickened nor with a rounded basal lobe. Plecia livida Smaller species, male wing length less than 5.8 mm. Male gonostylus sharply pointed, apically thickened or with a rounded basal lobe. -16 16. Male gonostylus apically pointed. Plecia assonensis Male gonostylus apically rounded. -17 17. Male gonostylus slender, basally with a rounded lobe projecting dorsally. Plecia maimensis Male gonostylus clavate, apically thickened, without basal lobe. Plecia conica 18. Larger species, body length 8.5-10.5 mm, female sternite VIII with hook-shaped appendage. 21. Crossvein R-M nearly to entirely obliterated, basal Radial sector reaches vein M. Male head conspicuously small. -22 Crossvein R-M distinctive. Male head normal-sized. -23 22. Veins Rs and M merged for some distance. Smaller species, 5.5-7.5 mm. Antenna stout with 5-segmented flagellum.

  ).

	Head (fig. 91): Length 0.92-1.21 mm (N=5), width 0.96-1.21 mm (N=5). Brown. Complex eye rather
	small, subspherical, prominent. Flagellum 9-segmented, length 0.47-0.65 mm (N=3).
	Thorax: Length 2.0-2.7 mm (N=8), width 1.8 mm (N=1). Dark brown, presumably black in life.
	Haltere pale brown.
	Wing (fig. 90): Length 5.3-7.0 mm (N=7), width 2.0-2.8 mm (N=7), length/width =2.52-2.82 (N=7).
	Light brown fumose, anterior part slightly darker, pterostigma inconspicuous. Veins light brown
	throughout. Costa extends to half-way between apices of R4+5 and M1. Humeral vein present. Subcosta
	relatively strong, terminating in Costa just above origin of R2+3. Basal part of Rs subparallel to M,

crossvein R-M nearly vertical. R2+3 of medium length, nearly straight to slightly sinuous. Fork of M rounded. Fork of CuA relatively short, just a little longer than stem. Wing vein measurements in Table

Penthetria lugens (Oustalet, 1870) (Figs. 14-15, 95-97)

	Diagnosis: A medium-sized, slender Penthetria. Body brownish, wings brown fumose. R2+3 slightly
	sinuous and oblique. On ventral side of abdomen gonapophysis VIII has a pair of digitiform
	appendages.
	Redescription:
	Male unknown
	Female (fig. 13) Total length 8.3-11.5 mm (N=4).
	Head (fig. 96): Length 0.93-1.11 mm (N=3), width 1.01-1.27 mm (N=3). Dark brown, probably black
	in life. Antennal flagellum probably 5-or 6-segmented.
	Thorax: Length 2.0-2.6 mm (N=4), width 2.0 mm (N=2). Dark brown, probably black in life. Haltere
	yellowish-brown.	5 mm (N=12), width 2.6-3.0 mm (N=11), length/width = 2.29-2.57
	(N=11). Light brownish, slightly darkened anteriorly, pterostigma indistinctive. Humeral vein present, Wing (fig. 95): Length 8.6-9.4 mm (N=4), width 2.9-3.3 mm (N=4), length/width = 2.87-3.34 (N=4).
	subcosta distinctive, long and straight. Costa extends to nearly half-way between apices of R4+5 and Brown fumose, R-veins brown, posterior veins concolourous with membrane. Costa extends nearly to
	M1. Basal part of Radial sector subparallel to M. R2+3 oblique, nearly straight. Fork of M rounded. apex of M1. Humeral vein present, Subcosta fine and short, terminating well before crossvein R-M.
	Wing vein measurements in Table 1. Fork of CuA not much longer than stem. CuP distinctive, Pterostigma indistinctive. R2+3 with a bend in basal third, otherwise nearly straight, oblique. R4+5
	straight. Wing vein measurements in Table 1. apically nearly straight. Posterior veins not possible to see in specimens at hand. Wing vein
	Legs: Not well preserved in any of the specimens at hand. Pale brown, tarsi a little darker. Fore tibia measurements in Table 1.
	length 1.8-1.9 mm (N=4). Legs: Brown, slender. Fore femur 2.0 mm (N=1), fore tibia 2.2 mm (N=1), hind femur 2.6 mm (N=1),
	Abdomen: Length 4.7-6.1 mm (N=11), width 1.5-2.3 mm (N=8). Brown, apically darkened. hind tibia 2.7 mm (N=1).
	Abdomen: Length 6.1-7.6 mm (N=4), width 1.7-2.9 mm (N=3). Light brown, relatively long and Terminalia: Dark brown, presumably black in life. Tergite VIII rectangular with slightly protruding hind corners. Sternite VIII mesally with a small, rounded indentation. narrow, spindle-shaped.
	Terminalia (fig. 97): Gonapophysis VIII with a digitiform appendage on each side. Cerci two-
	segmented, relatively long.
	Protomyia lugens Oustalet, 1870: 142-143.
	Plecia cf. lugens (Oustalet, 1870); Théobald, 1937: 227.
	Penthetria lugens (Oustalet, 1870); Handlirsch, 1908: 959.
	Material examined: Holotype (female) MNHN R 06666.
	Additional material: 2 females (MNHN B 24412, B 24518). 5 females (NHB F2208, F2230, F2323,
	F2410, F2413). 1 female (FSL 391923).
	Localities: Corent, Céreste, Kleinkembs
	The holotype specimen (fig. 12) is in very poor condition, wing venation and most details are
	impossible to see. Collomb et al. (2008) classified the type as Insecta, incerta sedis, though it is
	recognizable as a Plecia or Penthetria female. However, the diagnostic appendages on gonapophysis
	VIII are visible, confirming that the holotype is conspecific with Penthetria lugens sensu Théobald,
	1937.

Penthetria nervisinuata (Théobald, 1937) comb.n. (Figs. 16-17, 98-102) Plecia nervisinuata Théobald 1937: 407

	Bibiopsis funebris Heer in Heer & Gaudin, 1861: 153. (nec Penthetria funebris Meigen, 1804)
	(nomen nudum)

comb.n. (Figs. 18, 103-106)

	Plecia subterranea Théobald, 1937: 233.
	Plecia bigoti Brongniart, 1879 -unpublished manuscript name in a collection of EM
	Plecia gracilis Brongniart, 1879 -presumably an unpublished cabinet name in a collection of EM
	Material examined: Holotype (male) NMB F1404. Paratypes (males) NMB F1414/1, F1414/2.
	Additional material (2 males 11 females): EM 70002, 70009, 70010, 70011, 70013, 70015, 70017,
	70201 (A 10.9), 70202 (A 10.13), 70203 (A 10.70), 70204 (A 10.93) (all in Coll. Coquand, EM, stored
	in FSL)

  Terminalia (figs. 108-109): Hypopygium 0.70-0.77 mm (N=3) wide, broad and robust. Gonostyli 0.35-0.46 mm (N=3), short, robust, apically pointed. Epandrium mesally with a shallow, V-shaped cleft.

	Female unknown.

Plecia bucklandi

[START_REF] Heer | Die Insektenfauna der Tertiärgebilde von Oeningen und von Radoboj in Croatien. Zweite Abtheilung: Heuschrecken, Florfliegen, Aderflügler, Schmetterlinge und Fliegen[END_REF]

(Figs. 20-24, 110-113) Protomyia bucklandi Heer, 1849: 238-239. Protomyia elegans Heer, 1856: 36. Syn.n. Protomyia gracilis Heer, 1856: 36. Syn.n. Bibio edwardsii Oustalet, 1870: 130 Syn.n.

  5 mm (N=23).

	Female: Total length 8.7-10.7 mm (N=6)
	Head (fig. 124): Length 1.02 mm (N=1), width 1.01-1.07 mm (N=2). Black. Antennal flagellum rather
	slender, probably 8-segmented. Complex eye prominent. Ocellar tubercle low and indistinctive.
	Thorax: Length 2.5-2.9 mm (N=6). Black. Haltere light brown.
	Wing (fig. 123): Length 8.4-9.8 mm (N=3), width 3.4 mm (N=1), length/width = 2.53 (N=1). Light
	brown fumose, veins brown. Costa extending to apex of R4+5. Subcosta long and distinctive, humeral
	vein present. Pterostigma indistinctive. R2+3 rather long, curved. CuA with a long stem and short,
	rounded fork.
	Legs: Dark brown, rather short, slender throughout. Fore femur 2.2-2.3 mm (N=2), fore tibia 2.2-2.3
	Head (figs. 120, 122): Length 0.59-0.78 mm (N=12), width 0.63-0.96 mm (N=15). Rather short and mm (N=2), hind femur 2.6-2.8 mm (N=3), hind tibia 2.7 mm (N=2).
	broad, oval, complex eye prominent. Antenna length 0.41-0.62 mm (N=8), rather short and thick,
	flagellum 8-segmented. Ocellar tubercle small. Abdomen: Length 5.9-7.7 mm (N=6). Brown, cylindrical.
	Thorax: Length 1.7-2.7 mm (N=27), width 1.4-2.0 mm (N=16). Black. Sulci deep and distinctive.
	Haltere brown.
	Wing (fig. 119): Length 5.4-8.0 mm (N=26), width 1.9-3.2 mm (N=23), length/width = 2.10-2.87
	females, NMB
	F1496, F1530, F1565, F1600, F2044, F2059, F2060, F2089, F2103, F2131, F2177, F2242, F2287,
	F2389, F2406. 1 female, Aix-en-Provence FSL 391927. 5 females, EM 70003, 70004, 70005, 70012,
	70205 (A 10.95) (Coll. Coquand, stored at FSL).
	Additional material (5 females) NMB F2152, F2210, F2215, F2344, F2345.
	Localities: Corent, Kleinkembs.
	Diagnosis: A medium-large Plecia (total length 8.7-10.7 mm). Antennal flagellum probably 8-
	segmented. The species has highly distinctive female terminalia with a pair of strong, hook-shaped
	appendages on the last sternite.
	Redescription:
	Male unknown.

(N=23). Light brownish fumose, veins brown. Subcosta long and distinctive, humeral vein present. Costa extending to apex of R4+5. R2+3 slightly curved, oblique. Fork of M rounded. Pterostigma indistinctive. Wing vein measurements in Table 2. Legs: Brown, slender. Abdomen: Brown, spindle-shaped. Terminalia: Cerci short and indistinctive. Plecia inflata Oustalet, 1870 (Figs. 31, 123-125) Plecia inflata Oustalet, 1870: 142. Material examined: Holotype (female) NMB F1495. Terminalia (fig. 125): Dark brown. Last sternite much darker and heavier sclerotized than preceeding sternites. Last sternite with a pair of strong, hook-shaped appendages. Plecia lapidaria (Heyden & Heyden, 1865) (Figs. 32-33, 126-128) Protomyia lapidaria Heyden & Heyden, 1865: 25. Plecia lapidaria (Heyden & Heyden, 1865) Théobald 1937: 231-232. Plecia Bayleana Brongniart, 1879presumably an unpublished cabinet name in collection of EM Plecia Heeri Brongniart, 1879presumably an unpublished cabinet name in collection of EM Material examined: Syntype (female) of Protomyia lapidaria NHMUK In 58813. 15

Gentilini, 1993 (Figs. 34-35, 129-131)

Plecia larguensis

[START_REF] Gentilini | New species of Plecia from the Oligocene of Southeastern France[END_REF]

: 162 Material (tentative) (RGL) Bois d'Asson 5, Bois d'Asson 7, Dauphin 30, Bois d'Asson 47, Dauphin 182.

Plecia morio (Heer, 1849) (Figs. 47-48, 154-159)

  Bibio morio Heer is not to be confused with Bibio morio (Linnaeus, 1758) sensu Fabricius, 1787 (current name Hemipenthes morio[START_REF] Linnaeus | Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum caracteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata[END_REF]). This species was, however, described in the genus Musca and not in Bibio, so Bibio morio Heer is not a primary junior homonym.

	Material examined: 1 female (part and counterpart) NHMUK In 39831 and 39860. Females FSL
	391929, FSL 391941. MNHN Aix 411, 970, 1295, 1386, 1442. Syntype (female) of Protomyia
	collossea NHMUK In 58789.
	Male (tentatively associated) MNHN Aix 388, 885, 1398.

Bibio morio Heer, 1849: 222 Protomyia collossea Heyden & Heyden, 1865: 21.Syn.n.

Plecia collossea

[START_REF] Protomyia Gracilenta Heyden & Heyden | 1856). The type is in Landesmuseum Joanneum, Graz and an additional specimen from Aix-en-Provence is in ETHZ. Protomyia gracilenta was decribed from Rott, Plecia acutiventris and Bibio detractus from Aix-en-Provence. Material examined: Female identified as Bibio lignarius sensu Unger SLJG 259. Female (NHMUK In 39822). Holotype (male) of Protomyia gracilenta NHMUK In 58805. Cotypes (2 males 1 female) of Plecia guinieri EEFN (coll. Fliche) F 190. Cotype (female) of Plecia guinieri EEFN (Coll. Fliche) F 239. Holotype (male) of Plecia acutiventris FSL 391937 (A84), EEFN F 169 (status of both specimens given as "holotype[END_REF]) Statz, 1943: 14

Plecia lygaeoides

[START_REF] Heer | Die Insektenfauna der Tertiärgebilde von Oeningen und von Radoboj in Croatien. Zweite Abtheilung: Heuschrecken, Florfliegen, Aderflügler, Schmetterlinge und Fliegen[END_REF]

sensu

[START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF]

  ). Pigmentation of membrane and veins not preserved in any of the specimens at hand. Humeral vein and subcosta prominent, pterostigma indistinctive. R2+3 evenly curved, apical part of R4+5 rather straight. Fork of M relatively short. Wing vein measurements in Table3. Brown, anterior half somewhat darker. Veins brown, strong and distinctive. Humeral vein and subcosta prominent. Pterostigma indistinctive. R2+3 evenly curved, rather short, apical part of R4+5 nearly straight. Costa extends a little beyond apex of R4+5. Wing vein measurements in Table3.

	Head (figs. 156-157): Length 1.68-1.72 mm (N=3), width 1.72-1.84 mm (N=3). Brown. Antenna
	relatively long and slender, flagellum probably 9-segmented. Interocular pile not apparent.
	Thorax: Length 3.8-4.0 mm (N=3), width 2.8-3.2 mm (N=3). Brown, probably black in life. Haltere
	pale.
	Wing (fig. 154): Length 10.0-11.5 mm (N=3), width 3.5-4.0 mm (N=3), length/width = 2.77-2.90
	(N=3). Thorax: Length 3.0-4.1 mm (N=7), width 2.4-3.3 mm (N=4). Dark brown, probably black in life. Pile
	not apparent in the specimens at hand.
	Wing (fig. 155): Length 12.0-13.2 mm (N=8), width 4.2-4.7 mm (N=7), length/width = 2.66-3.09
	(N=7).

Legs: Not preserved in the specimens at hand. Abdomen: Length 8.5-9.2 mm (N=3), width 1.6-1.8 mm (N=3). Light brown, relatively long and slender. Pile not apparent in the specimens at hand. Terminalia: Dark brown. Hypopygium width 1.5-1.6 mm (N=3). Epandrium posteriorly with wide, Ushaped indentation. Gonostylus 0.90 mm long (N=1), slender, nearly straight.

Female: Total length 14.0-16.2 mm (N=7).

: Length 1.14-1.45 mm (N=4), width 1.22-1.64 mm (N=4). Brown, probably black in life, rather small. Antenna cylindrical, slender, flagellum 1.11 mm long (N=1), 9-segmented. Complex eye medium-sized, oval. Ocellar triangle low and indistinctive.

Théobald, 1937 (Figs. 51-52, 165-171)

	Bibio baumbergeri Théobald, 1937: 223.
	Bibio parenti Théobald, 1937: 224. Syn.n.

Bibio bayleyi Brongniart, 1879, presumably an unpublished cabinet name in collection of EM Material examined: Holotype (female) of Bibio baumbergeri NMB F456. Paratype (female) of Bibio baumbergeri NMB. Holotype (female) of Bibio parenti NMB F1372. Female (EM 70001, stored at FSL), labeled "Bibio Bayleyi".

Additional material -4 males NMB F1377/4, F1377/6, F2183, F2258; 7 females: NMB F1376/1-2, F1377/2-3, F1377/5, F454, F 2330. 8 females, Aix-en-Provence, Coll. Coquand, EM 70207 (A 10.3), 70208 (A 10.6), 70209 (A 10.44), 70210 (301 λ), 70211-70214.

  ). Yellowish fumose, R-veins yellowish, posterior veins colourless. Subcosta rather short, apically indistinctive. Costa extends to apex of R4+5 .Pterostigma indistinctive. Basal radial sector about three times as long as R-M. Wing vein measurements in Table4.

	Legs (figs. 168-169): Yellowish brown to dark brown. Fore femur length 1.9-2.6 mm (N=6), width
	0.71-0.91 mm (N=6). Fore tibia length 2.1-2.2 mm (N=2), width 0.41-0.56 mm (N=2), with spine
	approximately twice as long as spur. Hind femur length 2.4-4.5 mm (N=10), width 0.46-0.71 mm
	(N=10), clavate, hind tibia length 2.2-4.2 mm (N=7), slender, tarsi slender.
	Additional material: Males: MNHN Monteils 1 (counterpart Monteils 61), 54, 59, 79, 99 (counterpart
	Monteils 106), 114, Camoins 29. Females: MNHN Monteils 8,

Abdomen: Brown, cylindrical.

Terminalia (fig.

170

): Cerci short, curved and pointed.

Bibio celasensis

Théobald, 1937 (Figs. 53-55, 172-177)

Bibio celasensis

[START_REF] Théobald | Les insectes fossiles des terrains oligocènes de France[END_REF]: 139-140. Bibio conformans Théobald, 1937: 142. Syn.n. Bibio obtusa Theobald 1937:140 and Bibio tenuiapicalis Theobald, 1937

: 140 are also probably synonyms for this species, but we have not succeeded in finding the types of these species.

Material examined: Syntypes of Bibio celasensismore than 100 specimens on a plate 12X14 cm (MHNM). Most of them poorly preserved. Bibio conformansspecimen (female) depicted by

Théobald (1937, Pl. XXI, Fig. 12

) FSL 392012 -A19.

Heer, 1856 (Figs. 56-61, 178-183)

  While Bibio ungeri marginatus is synonymous with this species, Bibio ungeri s.str. is obviously another species entirely. A specimen in the Museum of Natural History, Vienna is a Penthetria species, while Heer's figure[START_REF] Heer | Die Insektenfauna der Tertiärgebilde von Oeningen und von Radoboj in Croatien. Zweite Abtheilung: Heuschrecken, Florfliegen, Aderflügler, Schmetterlinge und Fliegen[END_REF]: Plate XVI: 8) is of a specimen in Landesmuseum Joanneum, Graz which is obviously not a bibionid. This large and slender specimen, which is rather poorly preserved with head and legs missing, is apparently a brachyceran, and possibly belongs in Xylophagidae or Asilidae. The wing venation is hard to see but apparently there is a pointed anal cell and a closed discal cell in the wing.

	Material examined: Lectotype (herein designated) male NHMUK In 39833. This specimen was
	illustrated by Lyell & Murchison (1829) and later by Heer (1856, Fig. 14). Specimen NHMUK In
	39855 is the counterpart of the lectotype. Paralectotypes (males, herein designated) NHMUK In
	39825/39845 (part and counterpart), ETHZ S.N. 158 (part and counterpart). Holotype (female) of
	Bibio romani (FSL 391915). Paratype (male) of Bibio serresi (FSL 391905). Bibio ungeri v.
	marginatus (depicted specimen, male, Théobald 1937) FSL 391918, A 26, (female) FSL 391919, A38,
	(female) FSL 391920, A 87, (female) EEFN Coll. Fliche F 201.
	Other material: 1 male (ETHZ S.N. 131), 1 male (FSL 391904), 3 males (MNHN Aix 42, Aix 54, Aix
	584), one pair of wings, presumably male (ETHZ S.N. 137), 2 females (FSL 391908, 391909), 4
	females (ETHZ S.N. 131), 2 females (MNHN Aix 873, Aix 950), 1 female (MNHN B 24431).
	Redescription:
	Male: Total length 8.5-11.6 mm (N=30)
	Head (fig. 180): Length 1.43-1.87 mm (N=9), width 1.64-1.97 mm (N=7). Complex eye with dense
	and rather long, brownish pile. Antennal flagellum probably 7-segmented. Palp robust.
	Thorax: Length 2.9-3.8 mm (N=10), width 2.4-2.8 mm (N=3). Black, dorsally with long, dark pile.
	Haltere dark brown.
	Wing (fig. 178): Length 6.3-7.9 mm (N=11), width 2.6-3.5 mm (N=11), length/width = 2.38-2.65
	Bibio curtisii Heer 1856: 34-35. (N=11). Hyaline to light brownish, veins blackish, prominent throughout. Humeral vein prominent.

Bibio martinsi Heer in Heer & Gaudin, 1861: 153 (nomen nudum) Bibio ungeri marginatus

[START_REF] Oustalet | Recherches sur les insectes fossiles des terrains tertiaires de la France[END_REF]: 125. Syn.n. Bibio romani Théobald, 1937: 336 Syn.n. Bibio serresi Théobald, 1937: 336 Syn.n.

Localities: Aix-en-Provence.

Diagnosis:

A medium-sized-large Bibio (9.5-12 mm). Head normal-sized for genus, antennal flagellum seven-segmented. Male complex eye with conspicuous, long, dark pile. Wing hyaline with dark brown veins, humeral crossvein present between Sc and Costa in basal third, pterostigma black, conspicuous. Crossvein R-M short but distinctive. Veins CuA1 and CuA2 apically distinctively curved. Legs all black. The species is habitually rather similar to Bibio crassinervis Skartveit & Pika, 2014 from the Miocene site of Öhningen, but differs from that in having an obvious humeral crossvein, which is absent in B. crassinervis, as well as having the wing veins not quite as strong and prominent. Pterostigma brown, oval, prominent. Costa terminates just after apex of R4+5. Basal part of Radial sector about three times as long as R-M. Crossvein M-Cu joins M2 slightly beyond fork of M. CuA1 apically curved backwards. Wing vein measurements in Table

4

.

  : Dark brown, presumably black in life. Protibia with spine about three times as long as spur. Hind femur moderately stout and clavate, hind tibia evenly expanding towards apex, not conspicuously clavate, with short, robust spur. Hind tarsus slender. Fore femur 1.7-2.3 mm long (N=3), 0.55-0.72 mm wide (

Théobald, 1937 (Figs. 62-64, 184-187)

Bibio dislocatus Théobald, 1937: 224-225. Bibio consolida Théobald, 1937: 225. Syn.n. Plecia macroventris Théobald, 1937: 229

. Syn.n.

Material examined: Holotype (female) of Bibio dislocatus NMB F1378. Holotype (female) of Bibio consolida NMB F1379. Holotype (female) of Plecia macroventris NMB F1383.

Bibio major (Oustalet, 1870) comb.n. (Figs. 65-67, 188-197)

	Plecia major Oustalet, 1870: 114
	Bibio inflexus Théobald, 1937: 404.
	Material examined: Plecia major syntype (male) MNHN R 06693. Bibio inflexus holotype (female)
	EEFN Coll. Fliche F 273-274.
	Additional material: 41 males: UPMC Céreste 75; (all following RGL, currently stored in MNHN)
	Céreste 34

  5-11.2 mm (N=31). Entirely black, body pile not conspicuous.

	Head (fig. 193): Length 0.87-1.35 mm (N=10), width 0.98-1.35 mm (N=9). Conspicously small,
	width approximately half of thorax width. Flagellum 10-segmented, length 0.49-0.68 mm (N=5).

  . Since Heer did not illustrate the specimen from Aix-en-Provence it is uncertain if the specimen in ETHZ is the one recorded by Heer, though the specimen is labelled in Heer's handwriting. The Aix specimen in ETHZ labeled as B. moestus is most likely not conspecific with the specimens from Öhningen which form the type series[START_REF] Skartveit | Revision of Bibionidae (Diptera) named by Oswald Heer from the Miocene of Öhningen, Southern Germany[END_REF], but is probably a female of Bibio curtisii. The presence of B. moestus in French Oligocene sites is thus unproven, and we regard it as unlikely.

Bibio spectabilis

Théobald, 1937 (figs. 68, 198-206)

Bibio spectabilis Théobald, 1937: 333. Material examined: Holotype (female) of Bibio spectabilis FSL 391911. Paratype (female) of Bibio spectabilis FSL 391912. Additional material: Male (tentatively associated) EM 70215 (1.2.2) (stored in FSL). Males (MNHN Aix 52, 1377). Females (MNHN Aix 6

  . Nomen dubium. Holotype: FSL 391936. A female specimen, part of the wing visible but no systematically important characters possible to see. Belongs in the genus Plecia. Protomyia adusta Oustalet, 1870: 145. Nomen dubium. Holotype: MNHN. A very weak impression, is a bibionid but not further classifiable. Protomyia formicoides Oustalet, 1870: 150. Nomen dubium. Holotype: MNHN R 06681. Female specimen, total length approx. 6.5 mm. A very weak impression, not recognizable to genus but it is in all likelihood a bibionid. Protomyia fusca Oustalet, 1870: 145. Nomen dubium. Holotype: MNHN R 06672. Female specimen, very vague impression, wings and legs missing. Is probably a bibionid.

Acknowledgements

We are very thankful to the curators of the various museums for giving us access to and helping us find the material studied. Curators Emmanuel Robert, FSL, Lyon, Milena Pika-Biolzi, ETHZ, Zürich, Walter Etter, NMB, Basel, Sylvie Pichard, MNHM, Marseille, Jean Philip and Bertrand Martin-Garin, MPP, Marseille, Dino Frey and Wolfgang Munk, SMNK, Karlsruhe, Claire Mellish, NHMUK, London, Oleg Mandic, NHMW, Vienna and Martin Gross, SLJG, Graz all helped with this. Andrew Ross, National Museum of Scotland, Edinburgh gave us valuable help in locating and interpreting some type material. Biodiversity Heritage Library (http://www.biodiversitylibrary.org/) has proved to be a very valuable source for older literature, which greatly aided this work.

Additional material: 4 females, Coll. Coquand,EM: EM 70007,70016,70018,70206 (A 10.14).

Localities: Aix-en-Provence (Rott)

The species was described from Rott, Germany. It is seemingly not present in the material from Aix in MNHN, but there are four females in Coll. Coquand, EM (temporarily stored at FSL) which are probably conspecific with the holotype.

Diagnosis:

Redescription:

Male unknown.

Female: Total length 10.5-12.3 mm (N=4).

Head (fig. 161): Length 0.91-1.01 mm (N=3), width 0.97-1.10 mm (N=3). Flagellum length 0.68 mm (N=1).

Thorax: Length 2.8-3.0 mm (N=4), width 2.3-2.5 mm (N=3).

Wing (fig. 160): Length 8.7-9.5 mm (N=4), width 3.0-3.6 mm (N=4), length/width = 2.63-2.93 (N=4). Vein measurements in Table 3.

Legs: Length of fore femur 2.5 mm (N=1), fore tibia 1.7-2.5 mm (N=3).

Abdomen: Length 7.6-9.4 mm (N=4), width 2.5-3.0 mm (N=3).

Genus Bibio Geoffroy, 1762

The genus is usually easily recognized by the wing venation, the shape of the anterior tibiae as well as the general habitus. Surprisingly, we still found that a number of described species belonging to this genus had been placed in other genera, and some species placed in Bibio belonged to other genera. Bibio species are present from most localities except Chadrat and Barbeiras. In some (e.g., Aix-en-Provence and Monteils) they predominate while in others (e.g. Céreste and Bois d'Asson) they are relatively infrequent.