406 



UNITED STATES NATIONAL MUSEUM BULLETEST 224 



longer than the first three segments ; from the apex 3 

 bristles arise, the anterior element is as long as three or 

 more segments. Equally long bristles arise from the 

 apex of the second segment. Claws moderately sharp, 

 strongly curved at the apex, the pulvilli three-fourths 

 as long as the claws ; the empodium nearly as long as the 

 pul villus and strongly thickened at the base. 



"Wings : The marginal cell closed with a quite short 

 stalk. First posterior cell widely open; fourth pos- 

 terior cell closed with an exceptionally long stalk. Anal 

 cell narrowly open, ambient vein reaches to the alula ; 

 alula narrow and linear. 



Abdomen: The abdomen is only gently convex and 

 rather flattened. The proportions of the abdomen are 

 much as in Atomosia Macquart. These flies are less 

 slender and much broader than in Clariola Kertesz or 

 Goneccalypsis Hermann. Pile of abdomen dense, fine, 

 short, setate and appressed. There are seven tergites 

 present ; the lateral margin of the first tergite bears a 

 vertical row of 4 stiff, pale, moderately long, spinous 

 bristles; each succeeding tergite bears in the middle of 

 the lateral margin a well developed, curved, pale, stout 

 bristle. Terminalia completely hidden by the cupped 

 apex of the abdomen. 



Distribution : Oriental : Opeatocerus purparata West- 

 wood (1849). 



Genus Dichaetothyrea de Meijere 



Figukes 264, 673, 1347, 1356, 1577, 2120, 2126 



Dichaetothyrea de Meijere, Tijdschr. Ent, vol. 56, suppl., p. 

 58, 1914. Type of genus: Atomosia punetulosa de Meijere, 

 1911, by original designation. 



Minute, slender and punctulate flies. The abdomen is 

 elongate, subcylindrical, and the pile is minute, short, 

 and rather scanty. Antenna unusually elongate; the 

 third segment bears a long, slightly tapered, short plu- 

 mose or long pubescent microsegment and at its junc- 

 tion with the third segment is a dorsal spine. Vertex 

 deeply excavated; ocellarium high, with steep sides 

 and the face narrow. Length 7 or 8 mm. 



Head, lateral aspect : The head is of moderate length ; 

 each eye is quite convex anteriorly. The face is not 

 visible in profile except below, where it is slightly pro- 

 tuberant yet not produced as far as the middle of the 

 face. The occiput is micropubescent with 4 stiff, 

 rather short, sharp bristles situated dorsally but located 

 deeply within the dorsal recession between the eyes. 

 Proboscis quite short, small, cylindroid and thrust di- 

 rectly forward horizontally and not extending beyond 

 the facial protuberance. Palpus extremely small, with 

 two segments recessed beside the proboscis and not 

 visible in profile. The antenna is long and slender, the 

 first segment a little more than twice as long as the 

 second and with 1 long bristle below in the middle ; the 

 second segment has 2 ventral apical and 1 dorsal apical 

 bristle, besides a shorter bristle above and below. The 

 third segment is a little longer than the combined 

 length of the first two and divided into two portions ; 



the outer portion is two-fifths the length of the whole 

 segment and constitutes an extensive microsegment, a 

 little more slender but with considerable long micro- 

 pubescence; the dorsal apex of the basal section has 

 a distinct, very stout but rather short spine. 



Head, anterior aspect : The face is narrow, no more 

 than two-thirteenths the head width; it is slightly 

 widened below. Face entirely micropubescent, with a 

 pair of long, slender, bristly hairs above and 3 or 4 

 other shorter hairs above and below ; on the protuber- 

 ance are 2 still longer, slender, bristly hairs followed 

 by 2 submedial hairs, almost as long, on the lowest 

 margin; subepistomal margins with 2 pairs of long, 

 slender hairs unequal in length. The front is a little 

 wider above; ocellar tubercle high, with vertical sides 

 and a single pair of long, stiff bristles. Anteromedial 

 and centi-al facets of eye only slightly enlarged. 



Thorax : The thorax is slightly convex, without pile 

 medially on the anterior half but with short, recumbent 

 pile laterally. Notopleuron with 1 to 2 long, fine, stiff 

 hairs; 1 upon the postalar and 1 upon the supraalar 

 region. Scutellum with sparse, appressed, discal pile 

 and erect soft, short, marginal pile besides a pair of 

 conspicuous, long, stout, sharp, divergent, black bris- 

 tles. Prosternum and prothorax fully united. Hu- 

 merus pilose. Cervical region quite short. Pleuron 

 micropubescent, with 1 long, slender, bristly hair 

 posterodorsally on the mesopleuron. Mesopleuron and 

 sternopleuron distinctly fused without trace of suture. 

 Hypopleuron with 2 or 3 fine hairs. Metapleuron with 

 a vertical row of 4 quite long, slender hairs and a few 

 shorter elements in front. Lateral slopes of the meta- 

 notum distinctly pilose. 



Legs: The hind femur slightly thickened on the 

 distal half, with 1 slender, dorsoapical bristle and a 

 single, quite long, lateral bristle at the distal third. 

 Also present are several fine, long hairs ventrolaterally 

 and a fringe of long, erect, ventromedial pile. Hind 

 tibia of nearly uniform width throughout, with 3 quite 

 long, rather stout, dorsal bristles located at the basal 

 and apical third and also with long, more slender, ven- 

 tral bristles. Apex with short bristles below. Hind 

 basitarsus with long, stout bristles anteroventrally at 

 base and apex ; second segment with 3 bristles at apex. 

 Middle femur slightly swollen distally, with 1 fine, 

 dorsal bristle at the outer third and 1 subapical bristle 

 anteriorly. Middle tibia with 2 extremely long, bristly 

 hairs anteriorly near basal and apical third and 2 

 equally long, ventral hairs. Dorsal or anterodorsal 

 bristles are 3 in number and are more slender and only 

 half the length of the former. Anterior femur with 

 2 bristly hairs near the apex ; the tibia has 1 quite long 

 and 2 short, ventral, bristly hairs and with 3 long, 

 stouter, posterior, bristly hairs. The apex of the an- 

 terior tibia has a small, yet distinct spur or short spine 

 which is dorsal in position and easily overlooked. 



"Wings : The wings are slender, the alula is reduced 

 to a linear trace, distinct but less wide than the width 

 of the costal cell. Marginal cell closed with a short 

 stalk. Fourth posterior cell closed with a long stalk. 



