364 ERNEST A. BACK. 



Prof. C. W. Johnson first called my attention to the validity 

 of rufescens. There is no doubt that it is distinct from dis- 

 color with which it is associated in Aldrich's list. 



Deroinyia sallei (PI. VI, fig.. 3). 



Saropogon sallei Bellardi, Saggio, II, 70, 1861. 



Diogmites sallei O. Sacken, Biologia, Dipt., I, 174, PI. Ill, fig. 11. 



Deromyia sallei Williston, Biologia, Dipt., I, 311; oc. in many 

 Mexican localities. 

 % 9 -—Length 19-22 ynm. — -Rather slender yellowish species with 

 deep yellowish-brown or blackish wings; thorax and coxae rather 

 thinly pale golden pruinose, leaving on the dorsum two narrow and 

 two broader lateral stripes, besides other less distinct lines; bristles 

 of palpi, antennae, thorax and legs, except the coxae, black. 



Yellowish, sometiines tinged with a brownish color; the face and 

 front densely golden pruinose, the thorax less thickly so; the occiput 

 darker but concealed by a fairly dense golden bloom. Abdomen 

 nearly unicolorous, without darker spots on the lateral margins; the 

 extreme base, and sometimes the extreme lateral margins, pale golden 

 pruinose, but only so in certain lights. Bristles of mystax not dense, 

 yellowish or whitish, the remainder of the face without hair or pile 

 of any sort; front with only a few short black hairs near the orbits on 

 the vercex; ocellar tubercle with black bristles; upper occiput with 

 brownish bristles, the lower portion with more numerous and yellow 

 bristles and hair. Antennse and palpi reddish-yellow, with short black 

 hair; the first segment of the antennae without noticeable hair below, 

 and on all the segments the hair is comparatively short. Proboscis 

 black, yellowish at base. Thorax and coxae thinly golden pruinose. 

 The dorsum shows two narrow well separated median, and two broader 

 lateral stripes of the same brownish color; there are also spots of similar 

 color lying between the anterior ends of the lateral stripes and the 

 median stripes, and outside and confluent with the extreme anterior 

 ends of the median stripes. The median stripes extend from the pro- 

 thorax nearly to the base of the scutellum; the lateral ones, consider- 

 ably abbreviated anteriorly, likewise extend backward nearly to the 

 scutellum, becoming much attenuated behind and bisected by a line 

 of pale bloom along the transverse suture. Scutellum thinly golden 

 pruinose. Hair and bristles of dorsum black; pleurae without hair, 

 except sometimes on the upper part of the sterno pleurae, where it is 

 very inconspicuous and black; trichostical bristles black, surrounded 

 by pale pile. Legs yellowish, tarsi often darker; the coxae rather 

 sparsely clothed with pale bristles, the rest of the legs with short black 

 hair and long black bristles; the hair on the lower posterior side of the 

 front and iniddle femora pale. Claws black, pulvilli pale. Halteres 

 sordid yellow. Wings brownish or blackish, the centers of all the 

 posterior, discal, anal and axillary cells paler, but in varying degrees. 



