AMERICAN DIPTERA. 313 



Cinpis pelluci<la Coquillett. 

 Proc. Wash. Acad. Sci., 1900, p. 408. 



Black, the palpi and horny part of proboscis, except at base, yellow, halteres 

 yellowish white, bases of tibiae sometimes reddish yellow; eyes of male more 

 widely separated than the posterior ocelli ; third joint of antennae rather broad, 

 gradually tapering to the apex, about five times as long as the style, proboscis 

 twice as long as the height of the head ; hairs and bristles of body and legs black ; 

 mesonotum slightly polished, marked with a median, light gray pruinose vitta, 

 the lateral margins and pleura gray pruinose ; scutellum bearing four bristles; 

 abdomen highly polished, hypopygium of male small, almost bare, obliquely 

 ascending, destitute of elongate processes, central filament robust, rapidly taper- 

 ing to the apex, arcuate, free, except its apex; hind margin of fifth abdominal 

 segment ventrally fringed with spinous bristles, many of which are as long as 

 this segment; legs in both sexes simple, first joint of hind tarsi slightly thicker 

 than that of the front ones, hind femora spinose on the under side ; wings hyaline, 

 veins dark brown, normal, stigma brown. 6 mm. 



Alaska. 



Closely related to virgata Coquillett, but in that species the spin- 

 ous bristles on the ventral portion of the fifth abdominal segment 

 in the male are arranged in a round cluster, and none of them ex- 

 ceed one fourth the length of this segment; both sexes have the 

 mesonotum dark gray pruinose and marked with three distinct, pol- 

 ished black vittse. 



Empis ftiniMla Coquillett. 

 Proc. Wash. Acad. Sci., 1900, p. 409. 



Differs from the above description of pellucida only as follows: Palpi and pro- 

 boscis black, legs always wholly black, eyes of male less widely separated than 

 width of lowest ocellus, mesonotum highly polished, not distinctly vittate, scu- 

 tellum bearing six or more bristles, hypopygium quite thickly covered with 

 hairs, the central filament hidden, except, sometimes, its apical portion, wings 

 pale brown, more yellowish at base and in co.stal cell. 7 mm. 



Alaska. 



It is with hesitation that I have included this, the following, and 

 even the preceding species in the same group with virgata. In 

 more than one case has Mr. Coquillett arranged a series of species 

 the description of one of which depends upon the foregoing, until 

 at last a form is reached in no wise related to the first species, but 

 which depends on the first description for its recognition. In the 

 present instance pellucida depends on virgata, fumida on pellucida, 

 and injumata on fumida, but in no case but the first is mention 

 made of the peculiar and very conspicuous ventral process of the 

 males. 



TKANS. AM. ENT. SOC, XXVIII. (40) SEPTEMBER, 1902. 



