116 rROCEEDINGS OF THE NATIONAL RfUBEUM. vol.49. 



Female specimens will generally be taken by collectors when 

 attracted in the manner just described, and occasionally on windows; 

 rarely in any other way. Males, on the contrary, are never attracted 

 to animals, and are only to be fomid on foUage in the sun, or rarely 

 on windows. It will require much careful study to jfind and collocate 

 the sexes still unknown of the species now known from only one sex, 

 not to mention the probability of other species being in existence. 



Specific names used by Williston and Coquillett {'plagens, limata, 

 cruenta) seem to imply a bloodsucking habit, but no observations 

 have been published on these species, and Ostcn Sacken's note may 

 have suggested the names. 



Osten Sacken collected several females of S. atrij^es at Webber Lake 

 and a single one each of inurhana and cinerea; it is therefore a fair 

 presumption that atripes was the one which bit him. 



The larval habits are unknown. In the nearest related genus, 

 Atlierix, the larvae live in water in mountain streams.^ Other Lep- 

 tidae have various larval habits; Professor Comstock showed me 

 larvae of a species from the California Sierras which are ant-lions, like 

 Vermileo of Europe; he did not succeed in rearing the adult, which 

 remains unknown. 



Distribution. — Of the 22 known North American species, only three 

 occur east of the Rocky Mountain region, these tlii-ee also occurring 

 in the West along with the 19 others. California has 15 species; 

 Washington and Montana, 5 each; Colorado, 4; British Columbia, 

 Idaho, and Oregon, 3; other States and Provinces with smaller 

 number. One peculiar thing is that, from Colorado eastward, no 

 locahties are represented in collections (with the exception of one 

 specimen from Ohio and one from Alabama) until eastern Penn- 

 sylvania is reached. The species most widely distributed is what I 

 have called Mrta, which may, however, prove to be a complex; it is 

 represented from Alabama to Alberta, and from New Hampshire to 

 New Mexico. Atripes, the bad biter, occurs from Alaska to Colorado 

 and California. Even these, however, seem to occur only here and 

 there in the wide range mentioned. Most of the species are without 

 doubt extremely local in occurrence within their range. 



Acknowledgments. — Mr. J. E. Collin, Newmarket, England, lent me 

 the types of Bigot's six species. Mr. Charles W. Johnson, of the 

 Boston Society of Natural History, lent type material in Mrta, cin- 

 erea, and fiavipalpis. Director Samuel Henshaw, of the Museum of 

 Comparative Zoology at Harvard University, sent mo the material 

 collected by Osten Sacken in 1876 (26 specimens, in seven species). 

 Prof. Trevor Kincaid, of the University of Washington, sent his en- 

 tire collection in the genus, rich in Puget Sound material and con- 



» Aldrich, Ent. News, vol. 23, p. 159. 



