LAPHIUINAB 



ROBBER FLIES OF THE WORLD 



407 



End of discal cell adjacent to the end of the posterior 

 cell or very slightly shorter, so that the veins closing 

 these two cells form, or nearly form, a straight line. 

 Anal cell closed with a very short stalk. 



Abdomen: the abdomen is comparatively elongate 

 and only slightly wider distally. It is slightly convex 

 but becomes more convex on the posterior segments. 

 Seven segments are distinctly visible and all of them 

 rather strongly punctulate. Sides of the second to 

 sixth tergites with a rather long, but weak, lateral 

 bristle placed in the middle of the margin. First ter- 

 gite with a dorsal row of 3 or 4 equally weak bristles. 



Distribution : Oriental : Dichaetothyrea punctulosa de 

 Meijere (1911). 



Genus Bathropsis Hermann 



Figubes 251, 665, 1294, 1303, 1349, 1358 



Bathropsis Hermann, Nova Acta Acad. Caes. Leop.-Carol., vol. 

 96, p. 68, 1912. Type of genus: Bathropsis peruviana Her- 

 mann, 1912, by original designation. 



Small, black flies with the abdomen coarsely and 

 deeply punctate. The hind femur is swollen and the 

 face narrow. The antenna is exceptionally elongate 

 and quite slender and the spine of the third segment is 

 placed at the apex. They suggest Cerotainia Schiner 

 in general appearance and differ from this genus in the 

 narrow and convergent vertex. Length 8 to 10 mm. 



Head, lateral aspect: The head is of medium length 

 and strongly convex anteriorly. The face is very short, 

 scarcely visible in profile, a little more in evidence 

 below. The occiput is prominent, except on the upper 

 fourth, where the eye margins overhang it. Occipital 

 pile short, abundant and fine, with stout bristles be- 

 ginning above the middle and consisting of some 10 

 pairs. The proboscis is very short, robust, swollen 

 below at the base and the apex truncate. Palpus minute, 

 the first segment more or less fused to the base; the 

 second segment is short and cylindrical. Antenna at- 

 tached just below the upper third of the head and about 

 twice as long as the head, quite slender, the first seg- 

 ment slender and four times as long as the beadlike, 

 second segment; each of these segments bears several 

 slender, ventral bristles and some bristly pile below and 

 above. The third segment is of uniform width, the apex 

 rounded and bearing a spoon-shaped, dorsal depression 

 with spine. 



Head, anterior aspect: The head is but little wider 

 than high, yet nearly as wide as the thorax ; the face is 

 narrow, slightly divergent and below the antenna less 

 than a fifth the head width. It is unusually finely 

 micropubescent with pile restricted to 8 or 10 fine, scat- 

 tered hairs on the upper part and a narrow band of 

 more numerous hairs above the epistoma. Also there 

 is a vertical row on each side of 7 or 8 long, slender 

 bristles. Subepistomal area small and oblique. Front 

 distinctly divergent, convergent again at the vertex, the 

 sides with a V-shaped groove. Vertex deeply excavated, 

 the ocellarium high and narrow with a pair of stout 



535914 — 62— pt. 1 27 



bristles and 1 or 2 bristly hairs. Anterior eye facets a 

 little enlarged. 



Thorax: The thorax is rather low but short; the 

 mesopleuron is poorly developed anteriorly, as in At- 

 omosia Macquart. Surface of mesonotum densely cov- 

 ered with strongly curled and appressed short hairs, 

 nowhere differentiated. Humerus with stiff hair, tin- 

 lateral bristles moderately developed; there is 1 noto- 

 pleural 3 supraalar, 1 postalar and on the scutellar 

 margin a few, One, erect, not very long, marginal hairs; 

 the disc bears dense, curled pile. Mesoplenron with 2 

 bristles; the convex, anteriorly flattened metapleuron 

 with a band of moderately abundant, long, compara- 

 tively stiff bristles. Upper and posterior border of the 

 mesopleuron with scattered pile; the upper sterno 

 pleuron and posthypopleuron each bear a few hairs. 

 Propleural pile scanty. Prosternum continuous anil 

 fused. Middle of pleuron partly bare. Metanotal cal- 

 losity with a patch of bristles. Metasternum pilose, the 

 postmetacoxal area with a complete band of chit in. 



Legs: The femora are rather short and stout. The 

 dorsal pile is dense, appressed and setate; all bristles 

 are weak, but are strongest in the anterodorsal and 

 ventral rows of the middle tibia and posteroventral row 

 of the anterior tibia, where the bristles become long and 

 finely attenuate and each row has 3 or 4 bristles. The 

 hind femur is rather strongly swollen on the outer 

 third. Hind femur with 2 slender, dorsal, distal 

 bristles, the more medial ones nearer the apex and the 

 basal third with 2 longer, ventral elements. Ventro- 

 medial surface of hind femur and tibia each with a 

 dense band of rather long, erect, fine pile apparently 

 with glandular tips. Hind tibia stout with 4 or 5 

 slender, dorsal, distal lateral and 4 ventrolateral, longer 

 bristles. Claws fine, sharp; pulvilli and empodium 

 well developed. 



Wings: The wings are broad and slightly tinged 

 basally with brown; the closed marginal cell is rather 

 wide apically, with a moderate stalk; the anterior 

 branch of the third vein arises abruptly at nearly a 

 right angle; the posterior branch ends far to the rear 

 of the wing apex. Stalks of the fourth posterior and 

 anal cells long; the end vein of the fourth posterior 

 cell is oblique to the upper end vein of the discal cell. 

 The lower end vein of the discal cell is nearly as long 

 as the upper end vein. Other posterior cells widely 

 open. Alula short, the ambient vein evanescent, be- 

 ginning at the end of the fifth posterior cell. 



Abdomen : At the base the abdomen is nearly as wide 

 as the thorax and everywhere coarsely punctate. The 

 last three tergites are a little more narrow and more 

 convex. Six tergites in the male, the last moderately 

 cupped and emarginate, with a minute, concealed geni- 

 talia, and similar to Atomosia Macquart. Pile short, 

 subappressed and setate. Some tergites bear quite 

 stout, lateral bristles; the first tergite has 6 pairs, the 

 next two tergites each witli 3 pairs, the fourth bears 1 

 pair of bristles. 



Distribution : Neoi topical : Bathropsis basalts Cumin 

 (1930) ; peruviana Hermann (1912). 



