LAPHBIINAE 



ROBBER FLIES OF THE WORLD 



405 



shining and with abundant, short, subappressed pile; 

 the sides of the first segment have a radiating fan 

 of 7 pale, weak bristles and the middle of the lateral 

 margin of each remaining tergite has a single, pale, 

 weak but distinct bristle. The terminalia are visible 

 laterally and are only moderately conspicuous. 



Distribution : Ethiopian : Goneccalypsis argenteoviri- 

 dis Hermann (1907). 



Oriental: Goneccalypsis lucida Hermann (1912). 



Genus Opeatocerus Hermann 



Figures 283, 661, 1277, 1285, 1595, 2128 



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

 96, p. 106, 1912. Type of genus : Atomosia purpurata West- 

 wood, 1849, by original designation. 



Small, dark, short pilose, cylindroid flies with the 

 thorax and abdomen coarsely punctate. The face is 

 narrow, with nearly parallel sides and the deeply ex- 

 cavated vertex is no wider than the lower face. The 

 antenna is shorter than in Dichaetothyrea de Meijere ; 

 the first antennal segment is only a third as long as 

 in that genus and the terminal microsegment of the 

 third antennal segment is smaller, more strongly 

 tapered and not short plumose. Length 9 mm. 



Head, lateral aspect : The face is plane with the eye, 

 except on the lower third where it is gently produced 

 and rounded and retreating below. The eye is strongly 

 convex anteriorly and gently and distinctly convex 

 posteriorly. Occiput very short and only visible nar- 

 rowly along the middle of the posterior margin; its 

 pile is scanty and fine, a little longer on the lower fourth 

 of the head and short and very sparse in the middle; 

 bristles, about 9 on each side, begin just above the 

 middle and are remarkably stout and spikelike. Some 

 of the bristles are doubled and others are placed sub- 

 laterally and do not appear except posteriorly. The 

 proboscis is small, very short and stout with the apex 

 bluntly rounded. It is cylindrical and from the dorsal 

 aspect scarcely widened towards the base ; sides smooth 

 and polished; the base below is a little swollen. In 

 the unique type of Westwood's species it is thrust 

 obliquely downward but it does not extend as far as 

 the face. Palpus extremely short and cylindrical, with 

 a stout, apical bristle. I have not been able to deter- 

 mine if a basal segment is present. The antenna is 

 attached at the upper fourth of head; it is but little 

 longer than the head. The first segment is short and 

 about half as long as the second; the third is mod- 

 erately longer than the combined length of the basal 

 segment, is slightly narrowed at base and apex, is short 

 pubescent, and has a short, attenuate, indistinctly sep- 

 arated terminal microsegment which has somewhat 

 longer micropubescence and also a short, blunt, dorsal 

 spine at the point of attachment. 



Head, anterior aspect: The face is relatively narrow; 

 below the antenna it is about a fifth the head width. 

 The face is pubescent and bears 2 quite long, unusually 

 stout, strongly curved bristles on the lower protuber- 



ance besides 2 long, slender hairs lower on each aide, 

 along the subepistomal margin. Shortly below the an- 

 tenna on each side is a single long, moderately stout, 

 downward curved bristle shorter than those which 

 emerge at the epistoma. Middle of face with a vertical 

 row on each side of 6 to 8 shorter, fine, curved hairs. 

 The front is slightly widened, the vertex also, but not 

 wider than the lower face. Vertex deeply excavated 

 with slanting side. The high ocellar protuberance has 

 vertical sides and bears large, anterior ocellus and a pair 

 of long, stout, divergent, black bristles and 2 pairs of 

 quite short, fine hairs. 



Thorax: The mesonotum is deeply, coarsely punc- 

 tate, with a few, scattered hairs transversely across the 

 middle of the anterior mesonotum; there is dense, short, 

 subappressed pile laterally. Humerus pilose. The 

 notopleuron has at least 1 short, stout, black bristle, the 

 supraalar area has 1, postalar 1; the scutellum in the 

 unique type of Westwood's species is destroyed by mash- 

 ing. The metapleuron bears long and short pubescence 

 and 1 or 2 hairs. Mesopleuron micropubescent, with 1 

 small, weak bristle above. Anterior pronotum with 

 stiff hairs. Metapleuron with a fan of 7 long, pale 

 hairs, the lower 3 are quite long. Lateral metanotum 

 with bristles and pile. Postmetacoxal area with a 

 chitinized arch. 



Legs: All the femora and the anterior 4 tibiae are 

 pale yellowish brown. Posterior tibia 3'ellow basally, 

 dark brown beyond, all the tarsi quite dark brown. The 

 hind femur is rather strongly thickened, convex above 

 and not quite plane below; it bears a dense brush of 

 long, erect, ventromedial pile and 2 or 3 quite long, ven- 

 tromedial hairs; the middle element longest. The an- 

 teroventral margin has 3 or 4 almost equally long, fine, 

 bristly hairs. Hind tibia slightly arcuate, with long, 

 dense, erect, fine pile ventrally and with accentuated 

 bristles. There are 2 very long, ventral bristles, the 

 element at the basal third is extremely long and stout : 

 3 dorsal bristles, the middle and distal bristle long; also 

 with 2 lateral, long, stout bristles, the bristle located at 

 the distal third being especially long and stout. The 

 apex bears weak bristles, 2 laterally, 5 ventrally, pre- 

 ceded by a matted tuft of stiff pile. Apex of hind 

 basitarsus with a pair of quite long, stiff, dorsal, diver- 

 gent bristles. Middle femur slightly thickened, with a 

 few fine hairs below; beyond the middle, 2 of these hairs 

 are quite long; the middle of midfemur has well devel- 

 oped bristles consisting of 1 ventral at the basal third 

 and 1 at the apical third, both exceedingly long, oblique, 

 and stout. There are 4 anterodorsal bristles; the ele- 

 ments at the basal third and the apical third are ex- 

 tremely long and unusually stout; 2 weaker, dorsal 

 bristles are present. The apex bears 2 short dorsal ; 2 

 anterior, 4 central, and 2 posterior bristles. 



Anterior femur similar, the tibia likewise with long, 

 strong bristles, the posteroventral elements extremely 

 long and stout; the 5 ventral bristles, are shorter and 

 weaker, the 3 dorsal bristles moderately long and stout. 

 The anterior tarsi bear astonishingly long bristles; on 

 the basitarsus 1 bristle arises posterobasally, and is 



