314 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



11. Prevailing color of the legs yellow; cilia of the inferior orbit pale; 

 tegulse with black cilia; fourth longitudinal vein bent, but not 

 broken : 



1. Antennae altogether black; last joint of front tarsi in the male 



black, with a large lateral thumb-like projection; penultimate 

 joint likewise enlarged, triangular; tip of hind tibiae and hind 

 tarsi black : 



2. pollex n. sp. 



2, Basal joints of the antennae red; third joint red at base only, 



the rest black; front tarsi ^ with three long and slender 

 joints; fourth joint small, white; the last joint enlarged, lamel- 

 liform, black : 



3. canalieulatus Thorns. 



Two, more species are described by Mr. Thomson (Eugenics Resa, 

 512), J)oZ. metatarsalis $ 9, and Dol. aurifer $ 9. The descriptions are 

 wanting in some very essential characters, as for instance the color of 

 the cilia of the inferior orbit and of the tegnlae. Moreover, it is by no 

 means certain whether these species belong to the genus Dolichopus in 

 its present acceptation. 



1. Dolichopus corax n. sp. — Male. — Face dull yellow; cilia of the 

 inferior orbit black ; antennae black. Thorax and abdomen of a rather 

 dark metallic- green; pleurae very little pruiuose ; tegulae yellow, with 

 black cilia; hypopygium rather large, black; lamellae nearly black, yel. 

 lowish-brown in the middle only. Legs black ; front tarsi about once 

 and a third the length of the tibiae ; last joint expanded into a large black 

 lamel, which is fringed with short hair on the edge ; hind tibiae slightly 

 incrassated, shining on the inside, but on their latter half with an 

 opaque brownish streak. Fourth longitudinal vein very greatly bent ; 

 wings grayish, slightly tinged with brownish anteriorly. 



Female. — Hind tibiae not incrassated, and without the opaque brown 

 streak ; the other sexual marks also absent. Length 5-6"^™. 



Hah. — Webber Lake, Sierra Nevada, California, July 24-25, common. 

 ■Seven males and four females. 



2. Dolichopus pollex n. sp. — Male. — Face of a dull golden-yellow, 

 narrower toward the mouth ; cilia of the inferior orbit whitish ; anten- 

 nae black, third joint rather pointed. Thorax and abdomen metallic- 

 green, shining, sometimes coppery ; hypopygium with rather large, 

 whitish lamellae, bordered with black ; cilia of the tegulae black. Coxae 

 black, with a whitish pollen. Legs reddish-yellow ; front tarsi about 

 once and a third the length of the tibiae, whitish-yellow, the tips of the 

 first three joints black ; first joint more than one-half the length of the 

 tibia; second joint about one- third as long as the first; third joint 

 shorter than the second, slightly expanded toward the end ; fourth 

 joint nearly as long as the third, expanded, triangular, black; the fifth 

 is also black and still more expanded, inverted heart-shaped, with one 

 of the lobes much longer than the other, square at the end, thus form- 



