592 HOWARD 



plants by forming burrows and mines in various parts of them 

 but principally in the leaves. 



Ceratomyza dor salts Loew. 

 The transformations of one species of this genus are known 

 in Europe and its larv« mine the leaves of Sonchus oleraceus, 

 C. do7-salis has been reared at this office from a puparium found 

 in a mine in a leaf of timothy and similar rearings have been 

 made by Mr. F. M. Webster. The previous statements as to 

 breeding habits render the rearing of this species from human 

 faeces something of a surprise, yet it was unquestionably reared 

 on June 24, 1899, at Washington, from miscellaneous deposits 

 collected in a low part of the city on June 13. 



Desmometopa latipes Meig. 

 This insect, which occurs both in Europe and North America, 

 and which would hardly be expected to breed in human ex- 

 creta was reared, September 6, 1899, from a miscellaneous lot 

 of deposits collected in Washington August 18. 



Family EPHYDRID^. 

 This family includes a number of insects of curious struc- 

 ture and strange habits. The larva; as a rule are aquatic or 

 sub-aquatic and are found in waters strongly impregnated with 

 salts. They occur near salt wells, are found in the strongly 

 alkaline lakes of the Western States, some species breed in 

 pools of water strongly impregnated with manure and one 

 form is found breeding commonly in the pissoirs of European 

 cities. Brachydcutei'a argentata Walker, a handsome little 

 species belonging to this family, has been reared by the writer 

 from larvas found in a small pool, on the grounds of the Depart- 

 ment of Agriculture, which was strongly impregnated with 

 horse manure from an adjoining manure heap. 



Discocerina -parva Loew. 

 This species, found only in America and the breeding habits 

 of which are not known, was captured at Travilah, Maryland, 

 May 29, and June i, 1899, on human fiuces. It is a very 

 small, black, dull-colored and somewhat liairv species. 



