II. — Dipterous Larv^ from the Western Alkaline Lakes 



AND their use AS HuMAN FoOD. By S. W. WiLLlSTON. 



Through the kindiiess of Professors G. J. Brush and S. I. Smith I 

 have recently received a quantity of tlie larvje and iraagos of a dip- 

 terous insect that is of interest not only as one of the very, few inhab- 

 itants of the strongly alkaline lakes of the West, but as forming an 

 article of human food, the only instance that I am aware of in this 

 order of insects. The specimens, belonging to the genus Ephydra^ 

 were received with a quantity of the rare mineral Gay-lussite from 

 the Soda Lakes near Ragtown, Nevada. 1 find the following 

 description of the larger lake by Arnold Hague in King's Descrip- 

 tive Geology, vol. ii, pp. 746-749. 



" The lake is about five-eighths of a mile in diameter, with water of 

 a clear blue color, it has no outlet and is fed by a spring of cool fresh 

 water. The water is highly charged with alkaline salts and is so 

 dense that the human body floats in it without exertion, and, after 

 drying, the skin is left with a thin white covei'ing. 



" The water appears to be wanting in animal life, with the exception 

 of a minute fly, the larva of which is a small worm, accumulating in 

 such large quantities as to form a belt a foot wide along the shore. 

 It is occasionally gathered by the Pah-Ute Lidians, and, after drying 

 and pulverizing, made into a sort of meal or flour." From analyses of 

 the water made by Professor Allen its sj)ecific gravity is 1-0975, the 

 fixed residue in 1,000 jiarts being 114*7. This residue consists of 

 common salt, 64*94; sulphate of soda (Glauber's salts), 13-76; car- 

 bonate of soda, 29-24 ; sulphate of potash, carbonate of magnesia, 

 etc., 4-63. 



By comi)arison of these larvae with a number collected by Pro- 

 fessor Silliman, from Lake Mono, and kindly lent me by Professor 

 Verrill, I find them aj)parently quite the same. At my request Pro- 

 fessor Wm. H. Brewer has kindly given me the following description 

 of the lake and the flies, which will be read with interest. 



"My Dear Sir:" 



" You asked about the flies from Lake Mono, and, although I have 

 a sufiiciently vivid recollection of them, I have turned to a file of old 

 letters written to my friends at home at the time and on the spot." 



Tkans. Conn. Acad., Vol. VI., 1883. 12 July, 1883. 



