*S'. W. Williston — Dipterous Lamm from Alkaline Lakes. 89 



tastes unpleasantly from it, and that the Indians get fat and sleek. 

 There are many gulls about the lake at that season, 



"The flies settle on twigs, spires of grass, etc., until nothing of the 

 perch can be seen, merely a wand of closely clinging flies. They also 

 at times rest on the water in great numbers." 



In addition to these larvae a Phyllopod crustacean belonging to the 

 genus Artemia i^A. Monica Verrill) is, according to Professor Verrill, 

 found in large numbers in the waters of Lake Mono. This genus, 

 like Ephydra^ is, as stated by Professor Verrill, " remarkable for its 

 habit of living and flourishing best in very saline and alkaline waters 

 such as the natural salt lakes of Egypt, Utah, etc., and artificial 

 brines." (Am. Jour. Sci., xviii, p. 244, 1869, and Proc. Am. A. A. S., 

 1869.) 



The fly is small, black, and scarcely more than the sixth of an inch 

 in length. It belongs to the genus Ephydra, the larvae of many spe- 

 cies of which are known to inhabit saline or alkaline waiers. The 

 present species is perhaps new, but in deference to the opinion of 

 I^rofessor Packard, who compared these same Mono Lake larvae with 

 the larva? he described and named from Clear Lake, California, I 

 here describe the adult fly for the first time under the name of E. 

 Californica Pack. In a large number of larvte examined the difter- 

 ences were slight, the one here figured being one of the more slender. 



Larva of Ephydra (?) Californica. 



By comparison with the figure given of E. Californica (Am. Jour. 

 Sci., 3d ser., vol. i, p. 103) diflei'ences will be apparent. It differs 

 from the description in that the anterior end tapers abruptly, not 

 gradually, and the end is not truncate; the first four abdominal legs 

 are scarcely apparent, their presence being only indicated by the 

 short bristly booklets. Their identity will only be determined by 

 the comparison of the adults from Clear Lake. The description of 

 the'fly from the Soda Lakes is as follows : 



