AMERICAN DIFTERA. 321 



This species, wliich is associated with £. comantis only in locality, 

 must be further characterized thus : 



Male and Female. — Eyes of the male widely separated. The usual apical 

 femoral black spot is broadened in the male; the hind femora of the male are 

 curved and are provided with a large bifid tubercle on the under side at the 

 outer fourth, the inner spur of which is short, the outer provided with a bunch 

 of short black hairs, beyond this on the inner under edge of the femur is a small 

 mammiform process, beyond which is a fringe consisting of four small black 

 spine-like hairs; the hind tibiae are nearly straight, near the base on the inner 

 under side with a large tubercle, apically provided with a bunch of short black 

 hairs forming a spur-like pencil, distal to this on the outer under edge of the 

 tibia is a still larger tubercle, which is fringed outwardly by a series of long 

 black hairs. Metatarsi not enlarged, tarsi strongly spinose beneath. Hypopy- 

 giuin terminal, small, closed, central filament swollen at the exposed base, upper 

 laniellse projecting beyond the middle ones. Halteres black. The scutellar bris- 

 tles vary in number from six to twelve. The bristles in front of the halteres are 

 dense, about twenty in number. 



Numerous specimens from various parts of California. 



Empiiii claiida Coquillett. 

 Proc. Wash. Acad., 1900, p. 407. 



Black, the palpi, proboscis, humeri, lateral margins of metanotum, scutelluni, a 

 large spot below insertion of each wing, the halteres, coxpe and remainder of 

 legs, also base of venter, yellow, apices of tarsi brown ; eyes of male separated 

 less than width of lowest ocellus, third joint of antennfe broad at base, tapering 

 rapidly to the apex, about twice as long as the style, proboscis slightly over twice 

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

 opaque, gray pruinose, marked with four indistinct, brownish vittse ; scutellum 

 bearing four bristles; abdomen slightly polislied, hypopygium small, ascending 

 obliquely, the dorsal piece prolonged at each posterior corner in the form of a 

 flattened, almost linear process, central filament unusually robust, arcuate, free, 

 except toward its apex ; no ventral process in front of the hypopygium ; hind 

 femora of male each bearing a hook -like process on the under side a short dis- 

 tance before the apex, curved backward and covered with short hairs, while be- 

 yond it are two bare, pimple-like swellings; on the inner side of the femora, 

 nearer the apex, is a fringe of about five rather short spinous bristles ; hind tibise 

 of male each bearing a bare, slightly arcuate process on the outer side near the 

 base, while opposite it, on the inner side, is a low prominence beset with short 

 bristly hairs; legs of female simple, not fringed with scales; wings grayish hya- 

 line, stigma brown, veins brown, normal. 5-7 mm. 



Alaska. ^ 



Empis poplitea Loew. 

 Cent, iii, 29. 



3Iale and Female. — Cinereous, opaque, all the hairs and bristles short, black. 

 Head concolorous, black-pilose, eyes of the male separated. Anteunte black, third 

 joint elongated and strongly attenuated towards the apex. Palpi very small, tes- 

 taceous. Proboscis strong, black, bad ions above, nearly equalling twice the length 



TRANS. AM. ENT. SOC, XXVIII. (41) SEPTEMBER, 1902. 



