12S 



UNITED STATES NATIONAL MUSEUM BULLETIN 22 4 



Head, anterior aspect : The face is quite narrow and 

 rather strongly divergent below. The head is almost 

 circular, but slightly flattened, or depressed above and 

 below. It has short pile, directed obliquely downward, 

 except on the lower anterior portion, which is gently 

 produced but straight in profile and bears a lower mar- 

 ginal row of 5 pairs of moderately long, straight, quite 

 stiff, whitish bristles; above these bristles there is an 

 additional row of 2 or 3 pairs and still a little higher 

 an arched row of 4 bristles. Sides of front with 5 or 

 6 appressed, short, brownish yellow, bristly hairs. 

 Sides of ocellar protuberance each with a longitudinal 

 row of 3 somewhat longer, stiff bristles, which are 

 curved forward, the anterior element longest. An- 

 terior facets a little enlarged. The vertex has scarcely 

 any excavation, the ocellar protuberance very low, the 

 anterior ocellus directed nearly upward. 



Thorax : Mesonotum not very high, strongly convex 

 anteriorly. Mesonotum pollinose and everywhere 

 rather sparse, short, appressed pilose. Humerus an- 

 teriorly with 7 or 8 bristles. The lateral complement of 

 bristles consists of 2 long and 2 short on the noto- 

 pleuron, supraalar with 3, and postalar with 3 long, 

 stout bristles. Scutellar margin with a single pair of 

 long, stout, crossed bristles, 2 pairs of lateral bristles. 

 There is a widely separated, postdorsocentral row of 

 3 bristles on each side in front of the scutellum. Scu- 

 tellum flattened, pollinose but not pilose. Metanotal 

 slopes pollinose only. Hypopleuron, pteropleuron, and 

 mesopleuron micropubescent, without pile or bristles. 

 Metapleuron with 3 or 4 quite short, brownish yellow, 

 stiff bristles. Anterior pronotal collar with 7 pairs of 

 unusually long, stiff bristles. Upper anterior pro- 

 pleuron with 5 or 6 stout, yellow bristles. 



Legs: Anterior coxa is densely covered with stiff 

 bristles ; lower anterior margin of middle coxa similarly 

 covered, the posterior coxa with 3 lateral bristles. 

 Hind femur stout with appressed pile and short, stout 

 bristles. There are 5 lateral and 2 dorsolateral apical 

 bristles. This femur has 4 or 5 short, ventrolateral 

 bristles and an equal number of still shorter ventro- 

 medial bristles, both groups chiefly confined to the 

 outer half. Back from the apex is an oblique row of 3 

 long, stout, medial bristles; ventral pile short and ap- 

 pressed. Hind tibia short, appressed pilose and with 

 stout oblique bristles. This tibia has 4 dorsal bristles 

 beginning at the basal fourth, 4 ventral, and 4 or 5 la- 

 teral bristles; apical bristles are long and stout and con- 

 sist of 1 medial, 3 ventral, 1 lateral, and 2 dorsal. 

 Middle femur slightly thicker and a little shorter, with 

 2 anterior and 3 stout irregular posterodorsal subapical 

 bristles. Tibia with stout bristles : 3 dorsal, 3 or 4 pos- 

 terior, 2 ventral, 2 anteroventral, and 4 anterior bristles. 

 Anterior femur also somewhat thickened, especially 

 towards the base ; it bears a short, stout bristle dorsally 

 at outer fifth; its tibia has a double dorsal row each 

 with 3 or 4 bristles, a slightly longer posteroventral 

 row of 3. All these bristles are oblique and stiff. Apex 

 with 2 anterior, 2 dorsal, 1 posterior, and 3 ventral 

 bristles. Apex without spine. Claws long, rather 



blunt, the immediate apex acute but not sharp or slen- 

 der. Pulvilli and empodium as long as the claw; em- 

 podium swollen at base. 



Wings: The wings are broad, the marginal cell 

 open. The second submarginal cell is unusually short, 

 widely flared apically, with the anterior branch of the 

 third vein ending above the wing apex. The fourth 

 posterior cell is closed and stalked. Anal cell narrowly 

 open ; middle end vein of second basal cell quite short. 

 Alula large; ambient vein complete. 



Abdomen: The abdomen is at least as wide as the 

 mesonotum on the basal 3 tergites; it is slightly nar- 

 rowed from the base of the fourth tergite. The first 

 tergite is a little more than half as long as the second, 

 the first 4 are somewhat flattened, the remainder of the 

 abdomen is subcylindrical with more strongly curled 

 sides, the end of abdomen drooping. Sides of first 

 tergite with 2 or 3 stiff bristles; remaining tergites with 

 only short pile which is strongly appressed except on 

 the actual lateral margin itself. Eight tergites are 

 visible, the last tergite is only one-fifth as long as the 

 seventh. Female terminalia with a row of 4 or 5 short, 

 blunt, spines on each side which protrude only slightly. 

 Ventral plate divided in the middle. 



Distribution: Ethiopian: Ehacolaemus variabilis 

 Hermann (1907). 



Genus Ospriocerus Loew 



Figures 89, 457, 898, 907, 1722, 1728 



Ospriocerus Loew, Berliner Ent. Zeitschr., vol. 10, p. 29, 1866. 

 Type of genus : Asilus aodominalis Say, 1824, as Dasypogon 

 aeacus Wiedemann, 1828, described by Loew as a new 

 species, Ospriocerus aeacides Loew, 1866. Designated by 

 Back, 1909. 



Medium-size or large flies, the head nearly circular 

 from the frontal aspect. They are distinguished by re- 

 duced pile and numerous, stout bristles on the thorax, 

 legs, and head. The antenna is characteristically elon- 

 gate, especially the third segment, which is rather 

 flattened and somewhat widened. Most species are 

 black, with black wings and with the abdomen either 

 pale colored or dark. The abdomen is elongate and 

 tapered. Related to Stenopogon Loew, they are at once 

 separated by the presence hi that genus of a well de- 

 veloped miscrosegment attached to the third antennal 

 segment, In Ospriocerus it is generally absent, rarely 

 present and minute, and the third antennal segment is 

 more elongate, and differently shaped ; the wmgs are 

 generally broader. Length 16 to 30 mm. 



Head, lateral aspect: The head of medium length, 

 the face short on the upper half but considerably more 

 prominent below, clue chiefly to the anteroventral reces- 

 sion of the eye. The lower half of the face may be 

 slightly produced but in general the profile is nearly 

 plane. The occiput is tumid and strongly developed, 

 especially towards the medial portion, but slopes grad- 

 ually away from this area down to the eye margin. To 

 some extent the ventral exposure of the occiput is due 



