284 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



. Wings byaline ; veins dark brown ; venation exactly like that in Mr. 

 Philippi's figure of Anypenus. 

 Hah. — Tosemite Valley, California. One male specimen. 



Family ASILID^. 



In working up my western materials in the family Asilidce, I have 

 paid especial attention to the section of the Dasypogonina^ as the most 

 numerous and the most rich in peculiar generic foJms. I also described 

 a few of the more striking forms oi Laplirina. The section Asilina I have 

 altogether left out for the present, for the reason that the Asilina from 

 the Atlantic States are still in a state of confusion, and it will be better 

 to w^ork up all the species of this difficult group together. 



My Californian collection in the section Asilina is remarkably small, 

 which may in part be accounted for by the fact that these flies were 

 not in season yet when I left San Francisco for the Sierra Nevada in the 

 middle of July. Up to that date, I had only found a single species of Ma- 

 cJiimus (the Geysers, Sonoma County, May 5-7 ; also in Mariposa County, 

 and iu Tosemite Valley, in June) and an JErax (in Mariposa County). 

 In May, June, and the beginning of July, I often visited localities in Ma- 

 rin and Sonoma Counties, also in the immediate surroundings of San 

 Francisco (Lone Mountaiu for instance), where I could expect to find 

 Erax^Promaclms^ Proctacantlms, without finding a single specimen, while 

 Dasypogonina were abundant. In the Sierra Nevada, iu July, I found 

 an Erax, a Machimus^ a Tolmerus, mid a species respecting the position 

 of which I am iu doubt, and which occurred quite abundantly about 

 Webber Lake. 



The most striking peculiarities of the Californian fauna, as far as 

 known, consist in the occurrence of several genera of Easypogonina^ 

 hitherto not found anywhere else {AMautatus, Eicolonus, CaUiriicus), and 

 in the great abundance of species of Cyrtopogon, especially in the higher 

 regions of the Sierra Nevada. In one locality, Webber Lake, I found 

 thirteen species, nearly all on the same day, a number which exceeds 

 that of all the known European species. Eaulopogon also is well repre- 

 sented. 



The genus Nicocles^ hitherto found only in North America, is repre- 

 sented by two species in the Atlantic States and two in California ; one 

 occurs in Mexico. 



Clavator, if mj^ identification be correct, is common to California and 

 Chili. 



Among the genera characteristic of the western region in general, I 

 will name the following : — 



Ospriocerus, represented now by four or five species, occurs every- 

 where from Texas to California ; also in Mexico. It is not known to 

 occur outside of North America. 



Stenopogon, with ten described and many undescribed western species, 

 8cleropogon, with two described species, and 8aropogon, with two spe- 



