INSECT FAUNA OF HUMAN EXCREMENT 561 



States, nearly lOO species being known. jR. manca was cap- 

 tured at Washington on human faeces on the Potomac Flats. 



Family DOLICHOPODID^. 



The flies of this family are small in size and are usually of 

 metallic colors. The adults are predaceous like the Empididoe 

 and the slender cylindrical larvse live in the earth or in decom- 

 posing vegetable matter. 



Diaphorus leucostomus Loew. 

 The metamorphoses of the insects of the genus Dia^horus 

 are recorded by Schiner as unknown. The present species oc- 

 curs in the District of Columbia and Maryland, and was reared 

 in a single specimen on June i6 from the miscellaneous lot of 

 fseces collected on June 13. 



Dia-phorus sodalis Loew. 

 This species, originally described from New York, was cap- 

 tured by Mr. Busck in a privy at Twining City, Maryland, and 

 was both captured and bred by Mr. Pratt at Travilah, Mary- 

 land. The bred specimens issued from excrement deposited 

 May 29 and exposed two days. The captured specimens were 

 taken during the time of exposure and the bred specimens issued 

 sometime during June (exact date unfortunately not noted). 



Neurigona tenuis Loew. 

 The metamorphoses of the insects of this genus seem to be 

 unknown in Europe. The present species is an American form 

 and was captured May 16, 1899, on a fresh deposit at Wash- 

 ington, D. C. 



Family SARCOPHAGID^. 

 The name of this family implies that its species are flesh 

 feeders, but as a matter of fact they are rather variable in their 

 habits. The larvae of some feed upon the bodies of dead ani- 

 mals, others live in dung, in decaying vegetable matter and in 

 fruits, while others are practically parasitic on living insects, 

 and one genus {Sarcophila) is a parasite of mammalia and even 

 of human beings, depositing its young in the nostrils where 



