I.APHR1INAE 



ROBBER FLIES OF THE WORLD 



395 



tibiae. Protichisma. Hermann is also very close but has 

 longer, subclavate abdomen, less conspicuously exca- 

 vated postvertex. Length 8 to 14 mm. 



Head, lateral aspect : The head is short, the anterior 

 eye profile strongly convex. The face is very short, 

 sometimes slightly elevated below or towards the an- 

 tenna! base. Again it may be nearly as long throughout 

 as the width of the first antennal segment. Occiput in 

 profile scarcely visible, a little more in evidence through 

 the middle of the head. Its pile is fine, abundant or 

 scanty, the bristles where present are placed nearly in 

 the middle of each half of the occiput, few in number, 

 stout above. Proboscis small and robust, the apex ob- 

 tusely truncate, not extended beyond the face. Palpus 

 minute, the first segment broad and partly fused, the 

 second short and cylindrical, with a few long, ventral 

 hairs. The antenna is attached just above the middle 

 of the head ; it is quite elongate and slender and iy 2 to 

 nearly 3 times the length of the head. The first seg- 

 ment is unusually long and slender, 3 to 4 times the 

 length of the beadlike second. The third segment is as 

 long or longer than the first two, with dense, short 

 pubescence on the outer portion but never even short 

 plumose. Near but away from the apex is a narrow, 

 elongate excision which is rather inconspicuous and not 

 easily observed and carries a concealed spine. In some 

 species it is quite small. First and second segments with 

 long, bristly hairs; the first segment below near the 

 middle with a long, slender bristle. 



Head, anterior aspect: The head is unusually wide, 

 distinctly wider than the thorax and sometimes flattened 

 anteriorly. The face below the antenna is about a 

 fourth the head width and convergent below, its surface 

 micropubescent, with abundant or scanty, bristly pile 

 sometimes distributed over the whole surface. The 

 lower third of the face often has several pairs of slender 

 bristles or bristly hairs. Front strongly divergent with 

 a deep, V-shaped groove on either side; it is pubescent 

 and bears considerable fine pile in some species and 

 sometimes bristly hairs along the eye margin. Vertex 

 deeply excavated, wider than the front, the slanting 

 sides with abundant, long pile ; the high, narrow, peaked 

 ocellarium either with long pile or with a single pair 

 of distinct, generally slender bristles. 



Thorax: The thorax is comparatively short, some- 

 what more humped than in Atomosia; the pile dense, 

 subappressed and setate and undifferentiated on the 

 dorsum. The lateral bristles are generally weak and 

 consist of 1 notopleural and 1 supraalar, 1 postalar, and 

 no scutellar bristles; the scutellar rim and disc have 

 short pile. Mesonotum and scutellum punctured. 

 Propleuron and almost the whole of the mesopleuron 

 with abundant pile. Posterodorsal corner of the meso- 

 pleuron with only a bristly hair, the upper sternopleuron 

 with few hairs. The anterior mesopleuron bulges out- 

 ward and is prominent. Metapleuron unusually convex, 

 with a wide band of numerous, long, distally curved, 



bristly hairs. Metanotal callosity with numerous, quid' 

 stout bristles. Metasternum pilose throughout. Post- 

 metacoxal area with a complete chitinous arch. Pro- 

 sternum not di led. 



Legs: The legs are stout, especially on the first 

 femur; all the femora with a moderately abundant, 

 ventromedial mid ventral fringe of pile and on the hind 

 femur more poorly developed than Atomosia. Hind 

 tibial fringe well developed. Hind femur with 3 or 4 

 long, basally stout, ventral bristles near the base. Hind 

 tibia sometimes with rather dense, long, flatly appressed 

 pile and bristles absent or poorly developed, more often 

 there are 4 slender dorsal, 1 or 2 stout lateral, 3 or 4 

 ventrolateral bristles, and 3 ventral. Hind basitarsus 

 more or less swollen. Middle tibia with the anterodorsal 

 row of 3 to 5 bristles long and emphasized and witli 10 

 to 12 slender bristles or bristly hairs in 2 irregular rows 

 and 2 to 4 very long, ventral bristles, the basal ones 

 longest. Anterior tibia with 3 or 4 slender bristles 

 anterodorsally, 6 to 8 posteriorly, 4 or 5 longer postero- 

 ventral and 3 quite long slender ventral bristles. Cla ws 

 slender, sharp; the pulvilli and empodium well 

 developed. 



Wings: The wings are immaculate or tinged; the 

 marginal cell closed with a long stalk. Fourth posterior 

 cell closed and stalked, the stalk sometimes evanescent. 

 Remaining posterior cells open. Stalk of anal cell long, 

 the second submarginal cell comparatively narrow at 

 the apex, the end veins of the discal and fourth posterior 

 cells lie in the same plane, nearly or quite aligned or 

 offset by less than half the length of the discal end vein. 

 The second posterior cell may be narrowed or widely 

 open. Alula no wider than costal cell; ambient vein 

 ends with the second posterior cell. 



Abdomen: The abdomen is short, robust, coarsely 

 punctured, with the sides curved down ; the sixth ter- 

 gite forms a deep, emarginate cup concealing the minute 

 genitalia which are rather similar to Atomozia. Pile 

 coarse but subappressed, sometimes but not always 

 setate, and generally a little longer and erect laterally. 

 Only the first tergite bears lateral bristles and these are 

 generally weak. Males and females with six visible 

 tergites. 



Distribution: Nearctic: Cerotainia aZbipUosa Curran 

 (1930) ; atrata Jones (1907) ; macrocera Say (1823). 



Neotropical: Cerotainia argyropus Schiner (18G8) ; 

 argyropasta Hermann (1912); argyropyga Hermann 

 (1912) ; aurata Schiner (1808) ; bella Schiner (1867) ; 

 brasiliensis Schiner (1867); camposi Curran (1934); 

 dasythrix Hermann (1912) ; debilis Hermann (1912) : 

 fdubia Bigot (1878); fiavipes Hermann (1912); 

 feminea Curran (1930) ; jaimacen-sis Johnson (1919) ; 

 laticeps Bromley (1929) ; leonina Hermann (1912) ; 

 marginata Hermann (1912) ; minima Curran (1930) ; 

 fnigra Bigot (1878); nigripennis Bellardi (1801) ; 

 ornatipes James (1953); propinqva Schiner (1808); 

 rhopalocera Lynch Arribalzaga (1882) ; unicolor Her- 



