DASYPOOONI.NAE 



ROBBER FLIES OF THE WORLD 



175 



cox and Martin (1957) ; deserti Wilcox and Martin 

 (1957) ; howlandi Wilcox and Martin (1957) ; inyoi 

 Wilcox and Martin (1957) ; irvinei Wilcox and Martin 

 (1957) ; j-beameri Wilcox and Martin (1957) ; lestomyi- 

 formis Wilcox and Martin (1936) ; minusi Wilcox and 

 Martin (1957); minutus Wilcox and Martin (1936); 

 monrovm Wilcox and Martin (1936) ; neocvlatus Wil- 

 cox and Martin ( 1957) ; mvadensis Wilcox and Martin 

 (1957) ; nigricolar Coquillett (1904) ; nitidus Wilcox 

 and Martin (1957); oculatus Wilcox and Martin 

 (1936) ; richardsoni Wilcox and Martin (1957) ; sequoia 

 Wilcox and Martin (1957) ; stonei Wilcox and Martin 

 (1957) ; timberlakeiWilcox and Martin (1957) ; tolandi 

 Wilcox and Martin (1957) ; vanduzeei Wilcox and 

 Martin (1936) ; vandykei Wilcox and Martin (1957). 



Genus Cycloscerus Bezzi 



Figures 139, 495, 973, 982, 1973, 2027 



Cycloscerus Bezzi, Mem. Soc. Ent. Italiana, vol. 5, p. 60, 1926. 

 Type of genus : Cyrtopogon platycerus Villeneuve, 1913, by 

 original designation. 



Small flies with prominent, rounded, dome-shaped 

 face characteristic of Cyrtopogon Loew but with the 

 abdomen extremely bare and reduced in pilosity and 

 the pile generally reduced everywhere. The third an- 

 tenna! segment is compressed laterally and much ex- 

 panded ventrally and the proboscis unusually short 

 and stubby. Length 10-12 mm. 



Head, lateral aspect : The head is unusually long, the 

 face is unusually prominent from the antenna to the 

 epistoma, rounded and dome-shaped, the eyes strongly 

 recessive anteroventrally but the recession begins well 

 above the middle of the head. The occiput grows in 

 thickness and exposed area accordingly and is obliter- 

 ated only near the vertex. Pile of occiput fine, moder- 

 ately long and abundant only below; there are 9 pairs 

 of weak, finely attenuate bristles dorsally. The pro- 

 boscis is exceptionally short, thick, and stubby, with 

 bluntly rounded apex not reduced in width. It does not 

 extend out farther than the epistoma itself. There are 

 a few minute hairs at the apex, a number of moderately 

 long hairs at the base, and the medial ridge is well 

 developed in the middle. It is directed nearly straight 

 forward. Palpus clearly of two segments but short 

 and stout ; first segment excavated; second microporate, 

 each with a few stiff hairs. The antenna is attached a 

 little below the upper third, the first segment is un- 

 usually short and a little shorter than the second seg- 

 ment ; the second segment is compressed laterally, bead- 

 like, densely long pubescent, with a fuzzy appearance. 

 The third segment, the microsegments excluded, is twice 

 as long as the second segment; its greatest height is 

 more than half its length and it is gently widened from 

 the base to the middle and it is abruptly reduced in 

 height beginning at the outer fourth. It bears an ex- 

 tremely short, ringlike microsegment to which is at- 

 tached a second much longer, attenuate microsegment 

 bearing a minute, apical, hyaline spine. First antennal 



segment ventrally at apex with 2 or 3 long, quite stout 

 bristles. Third segment in the middle below with 3 

 such long, stout bristles and dorsally with 3 others 

 nearly as long. 



Head, anterior aspect: The face below antenna is 

 one-third of the head width and rather strongly diver- 

 gent below. Subepistomal area short and only slightly 

 oblique, slightly concave, and pubescent. Face pubes- 

 cent and, except for a triangular bare area on the upper 

 lateral portion, densely covered with numerous, moder- 

 ately long, weak bristles and with a few stiff hairs above 

 and ventrally along the eye margin. The pile and 

 bristles do not quite reach to the antenna and for the 

 most part are curled obliquely downward. The front 

 is rather strongly divergent, the vertex very slightly 

 narrowed and shallowly excavated. The sides of the 

 front bear numerous, long, erect, stiff hairs and 4 or 5 

 quite weak bristles. Ocellar protuberance small, the 

 ocelli not large and bearing 4 or 5 pairs of short, stiff 

 hairs. Eye facets enlarged centrally and with lateral, 

 depressed, hexagonal margins. 



Thorax: The thorax is densely covered with fine 

 micropubescence including the pleuron. The meso- 

 notal pile is stiff, erect, moderately long and abundant. 

 There is acrostical, dorsocentral, and humeral pile pres- 

 ent. The lateral bristles are moderately stiff and long 

 and consist of 2 notopleural, 2 supraalar, 4 postalar, 

 and 4 pairs of weak, long scutellar bristles. Scutellum 

 convex, with a number of fine, scattered, erect hairs. 

 Propleuron with fine, slender, abundant hair on the 

 collar posteriorly and more densely on the lateral ele- 

 ment. There are a few long, stiff hairs dorsally on the 

 mesopleuron, more abundantly on the posterior portion 

 and there is fine, long pile on the upper sternopleurcn. 

 Pteropleuron and hypopleuron without pile, meta- 

 pleuron with numerous, long fine hairs and 4 weak 

 bristles. Metanotal slopes bullose, micropubescent 

 only; slopes of metasternum with long pile, the ventral 

 metasternum with much long pile ; postmetacoxal area 

 membranous; tegula pubescent only. 



Legs: The femora are stout without being greatly 

 thickened. The hind femur bears dense, short, ap- 

 pressed setae above and rather long, scattered, fine, 

 erect pile laterally and below with a fringe of especially 

 long ventromedial hairs. It bears a tranverse cluster 

 of 9 bristles dorsally near the apex, and immediately 

 behind are 2 dorsolateral and 2 or 3 dorsomedial 

 bristles. This tibia bears moderately long, finely at- 

 tenuate, strongly curved bristles consisting of 9 dorsal, 

 6 medial, 5 middorsal, 3 or 4 dorsolateral, 4 lateral, and 

 4 stout ventral bristles. The apex bears 3 medial, 3 

 dorsal, 3 lateral, and 4 ventral bristles. The middle 

 femur has 9 anterior and 2 posterior bristles at the 

 apex; its tibial bristles are strongly appressed and con- 

 sist of 7 long, curved anterodorsal, 5 posterodorsal, 

 6 posterior, 4 or 5 ventral, and 5 anterior bristles ; apex 

 with 12 long bristles. Anterior femur with 2 or 3 weak 

 bristles anteriorly near the apex; its tibia with a double 

 row of dorsal bristles, each row containing 8 or 9 ele- 

 ments, and a double row of posterior ones, each con- 



