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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



portions with fine pile; postmetacoxal area membra- 

 nous ; presternum dissociated. 



Legs : The femora and to some extent the tibiae and 

 tarsi unusually elongate and slender. Hind femur 

 especially attenuate, with the apical fourth clavate. 

 Pile reduced to a few scanty, fine, appressed setae. 

 Bristles greatly reduced hi number, especially on the 

 femur. The hind femur bears 3 lateral bristles and on 

 either side at the apex 2 rather prominent stout bristles, 

 1 above the other. Also near the middle are 2 medial 

 bristles. Middle femur with 1 or 2 anterobasal bristles, 

 1 long, stout, ventral, basal bristle, which is rather 

 characteristic, and at the apex 2 stout anterior and 1 

 posterior bristle. Anterior femur similar, the ventral 

 element lacking, and the apical element reduced to 1 

 bristle. Posterior tibia swollen towards the apex, with 

 4 slender reduced bristles in each dorsal row, and 2 or 3 

 ventrolateral bristles. There are 4 rows on each of the 

 remaining tibia with 5 elements in the posterior row 

 of the middle tibia. Protibia with a short process and a 

 short, robust, pointed spine. Basitarsus with an ele- 

 vated flange and instead of denticles there are spinous 

 setae. Claws slender, sharp. Pulvilli and empodium 

 well developed. 



Wings : The wings are broad, the marginal cell widely 

 open; base of the second submarginal cell often with 

 a spur vein. Anal cell closed and stalked; fourth 

 posterior cell closed with a short stalk and its end vein 

 forms a right angle with the lower end vein of the discal 

 cell. 



Abdomen: The abdomen is elongate, slender, cylin- 

 drical, least wide at the end of the second tergite 

 and slightly widened beyond. The pile is greatly 

 reduced to fine, scattered setae more numerous on the 

 terminal tergites and sternites and also longer. Only 

 the first tergite with bristles, and these may be absent 

 or consist of 2 stout pairs. Males with eight tergites, 

 the eighth tergite extremely short and almost concealed. 

 Females with eight tergites, the last being large. Male 

 terminalia strongly rotate, the epandrium large, shield- 

 like with only a very shallow posteromedial indention 

 and no cleft. Gonopod well developed. Hypandrium 

 small. Female terminalia with 6 pairs of short, small 

 spines upon the acanthophorites. 



Distribution: Neotropical: Deromyia fulvipes Phi- 

 lippi (1865) ; fuscipennis Blanchard in Gay (1852) 

 [=fascipennis Philippi (1865)]; gracilis Philippi 

 (1865). 



Genus Cyrtophrys Loew 



Figubes 180, 552, 566, 1091, 1100, 1893 



Cyrtophrys Loew, Bemerkungen iiber die Faniilie Asiliden, p. 3, 

 1851. Type of genus: Cyrtophrys attenuatus Loew, 1851, 

 by in ono typy. 



Moderately large, pale, slender, elongate flies with 

 somewhat drooping abdomen, unusually elongate an- 

 tenna and greatly reduced pile and bristles. Belated 



to Mirolestes Curran and separated by the long antenna. 

 Length 12 to 18 mm. 



Head, lateral aspect: The face is rather well devel- 

 oped above and slightly more prominent below, where 

 it is obtusely triangular. The eye is strongly convex 

 anteriorly, very slightly convex in profile behind and 

 almost plane over much of the middle portion. At most 

 it is very slightly recessive below. The occiput is 

 scarcely visible in profile, obliterated above and only 

 narrowly visible below. The pile is restricted to a few 

 scattered hairs below and along the middle 10 or 12 

 stiff hairs. Bristles are restricted to a short, weak, 

 appressed pair near the upper fifth of the occiput and a 

 stout, conspicuous pair located deep behind the vertex. 

 The proboscis is strongly compressed laterally, gently 

 convex on each side, with unusually high, thin, medial 

 ridge which, however, does not begin until a short dis- 

 tance from the base, at once reaches its greatest height 

 and then tapers away completely on the apical third. 

 The apex is bluntly pointed, plane below, tapered and 

 rounded above with a few fine hairs at the apex and 

 6 fine hairs in the middle below. The proboscis is 

 swollen only from the dorsal aspect towards the base 

 and is directed nearly straight downward. Palpus 

 clearly of two segments ; the first segment is excavated, 

 second segment porate and with subapical attachment ; 

 both segments have long, stiff hairs ; ventrally the apex 

 of the second segment bears 5 or 6 stiff bristles. The 

 antenna is placed at the upper fifth of the head ; it is 

 unusually long and slender ; the first segment is barely 

 longer than the second. The third segment is three 

 times as long as the basal segments combined, it is slen- 

 der, of nearly uniform thickness, obtusely rounded at 

 the apex with slight dorsal, subapical reduction in 

 thickness; dorsally at the middle there is a clear exci- 

 sion bearing a small, distinct spine. First two segments 

 with a few, long, stiff hairs below and again at the apex 

 above. Third segment with 8 dorsal setae on the basal 

 half. 



Head, anterior aspect: The face below antenna is 

 about one- fourth of the head width, with parallel sides ; 

 the subepistomal region is long, oblique, nearly plane, 

 with medial ridge and bare. The face is micropu- 

 bescent with a few scattered hairs below, and with 2 very 

 long, stout, and 2 short, very slender bristles on the epis- 

 tomal margin, none along the subepistoma. Front 

 slightly divergent, the vertex slightly convergent. The 

 front is short, polished, with 2 or 3 minute hairs and 

 linear pubescence along the eye margin. Vertex only 

 moderately excavated, the sides nearly vertical, the ocel- 

 lar protuberance quite low and bearing 2 minute hairs 

 behind. Eye facets centrally enlarged. 



Thorax: The thorax is densely pollinose, including 

 the pleuron where the cover is more in the form of mi- 

 cropubescence. The mesonotal pile is restricted to a 

 very scanty row of dorsocentral elements containing 

 only 6 or 7 hairs anteriorly and 4 fine hairs on the pos- 

 terior half, 1 short and 1 long, slender bristle ; acrostical 

 elements absent. Humerus with only 1 or 2 hairs. The 

 lateral bristles are long, stout and strongly attenuate 



