556 



UNITED STATES NATIONAL MUSEUM BULLETIN 224 



Wings: The marginal cell unusually wide but the 

 wing is not expanded anteriorly ; this cell is closed with 

 a short stalk. The two branches of the third vein end 

 about an equal distance above and below the apex of 

 the wing. Anterior crossvein distinctly oblique, enter- 

 ing the discal cell a little beyond the middle. The 

 lower end vein of the discal cell is two or three times 

 as long as the upper vein and drawn towards the base 

 of the wing. Fourth posterior cell closed with a mod- 

 erately long stalk. The second basal cell ends ia two 

 veins. Anal cell closed. Alula wide, the ambient vein 

 complete. 



Abdomen : The abdomen is slightly tapered or with 

 nearly parallel sides; it is a little more than two-thirds 

 as wide as the mesonotum. The first tergite is rather 

 strongly protuberant laterally and bears a single, very 

 long, stout, black bristle and numerous, long, erect, 

 stiff yellowish hairs. There are seven tergites present 

 in the female, the eighth is included in the ovipositor 

 and is as long as the seventh. The ninth segment is 

 half as long as the eighth and the tenth of the same 

 length. The ovipositor is short and strongly com- 

 pressed laterally. First stemite apilose; the base of 

 the second has 3 or 4 fine, long hairs on each side, re- 

 mainder of sternal pile short and quite fine. 



Distribution: Oriental: Epiklisis pilitarsis Becker 

 (1925). 



Genus Neoitamus Osten Sacken 

 FiGTJBES 330, 344, 636, 1508, 1517, 2274, 2305, 2441, 2466 



Itamua Loew, Linnaea Entomologica, vol. 4, p. 84, 1849. Type 



of genus: Asilus cyanurus Loew, 1849. Designated by Co- 



quillett, 1910, the first of four species. Preoccupied, Co- 



leoptera, 1846. 

 Neoitamus Osten Sacken, Catalogue of the described Diptera 



of North America, ed. 2, Smithsonian Misc. Coll., vol. 16, pp. 



82, 235, 1878. Change of name. 

 Trichoitamus White, Papers Proe. Roy. Soc. Tasmania, 1916, p. 



91, 1917. Type of genus: Asilus rudis Walker, 1855, by 



original designation. 



Small or medium size flies, the upper face plane with 

 the eye, the lower half with an abruptly developed, con- 

 spicuous gibbosity. The upper occipital bristles are al- 

 most always proclinate and dorsocentral bristles gen- 

 erally well developed anteriorly. Metanotal callosity 

 pilose or bristly. The tergites have distinct bristles pos- 

 terolaterally, the venation is similar to Asilus Linne 

 but with the second posterior cell only gently and 

 moderately widened basally. In the females the ovi- 

 positor is formed by the last five segments, which are 

 narrowed and laterally compressed. Length 15 to 22 

 mm. 



Head, lateral aspect : The head is of medium length. 

 The eye is strongly convex anteriorly, plane posteriorly 

 except on the lower fifth, where the eye is posteroven- 

 trally recessive. The upper half of the face is plane 

 with the eye; the lower half has a prominent gib- 

 bosity which tends to have flat, lateral margins and is 

 generally abruptly developed dorsally. The occiput is 



only moderately prominent, a little better developed 

 near the vertex and bears rather loose pile ventrally 

 with bristles beginning at or just below the middle. 

 These occipital, bristles are slender and with few ex- 

 ceptions strongly proclinate at the vertex. The pro- 

 boscis is comparatively slender with a low, dorsal keel; 

 the base at most is very slightly swollen and the apex 

 bluntly rounded, with a few fine hairs. Palpus cylin- 

 drical, of moderate length, pilose with weak apical 

 bristles. The antemia is attached a little above the 

 upper third of the head ; the second segment short and 

 about half as long as the first segment. Both of these 

 segments bear numerous, slender, bristly hairs ventrally. 

 Third segment slender, generally not as wide as the 

 second segment, widest subbasally and attenuate. It 

 is approximately as long or slightly shorter than the 

 combined length of the first two segments and bears a 

 distinct microsegment and a style of nearly the same 

 length as the third segment. 



Head, anterior aspect : The head is nearly or quite as 

 wide as the thorax, nearly circular, especially if the 

 total height is considered, although the cheeks are of 

 moderate extent. The face below the anteima is quite 

 narrow and in the type of the genus is only about a 

 tenth the head width. Below the antenna the face may 

 be slightly narrowed and then is strongly divergent. 

 The upper half is pubescent, generally without pile, 

 although there may be a subocular row of longer pubes- 

 cence. The bristles of the gibbosity tend to be re- 

 stricted to the middle, extend over its whole length, are 

 numerous and long, but slender and extend down the 

 sides of the oblique subepistoma. The front is wider 

 than the upper face and the vertex slightly narrowed. 

 Front poUinose, with a single sublateral band of bristly 

 pile in 2 irregular rows. Vertex but little excavated, 

 with slanting sides and large ocellarium, carrying 2 or 

 3 pairs of bristles between the ocelli and a like number 

 behind. 



Thorax : The mesonotum is high and rather strongly 

 arched both anteriorly and posteriorly. It is pollinose 

 laterally and generally pollinose on submedial stripes. 

 The pile is scant, distinctly bristly in character, rather 

 long and suberect, with an extensive, submedial, bare 

 area beginning posteriorly to the humerus. Acrostical, 

 bristly pile is well differentiated. The dorsocentral ele- 

 ments become long, slender but prominent at a point 

 corresponding to the posterior plane of the humerus. 

 Humerus pilose, the lateral complement of stout bristles 

 contains: 3 notopleural, 1 or 2 supraalar, 1 supraposta- 

 lar, 3 or 4 postalar, and 1 to 3 pairs of scutellar bristles. 

 The scutellum is rather thick and convex with distinct, 

 impressed rim and scattered, erect, stiff hairs. Prono- 

 tum with a few, weak bristles. The upper border of the 

 mesopleuron has a fringe of long, stiff pile and gen- 

 erally few or no hairs posteriorly. Upper pteropleuron 

 with several bristles, the posterior basalare has several 

 bristly hairs. The upper posterior comer of the stemo- 

 pleuron has numerous, fine hairs. Posterior liypopleu- 

 ron and metapleuron each with a vertical band of hairs 



