INSECT FAUNA OF HUMAN EXCREMENT 



577 



species on both Continents. The former doubt as to the identity 

 of European and American specimens has recently been dis- 

 pelled by Dr. Gary de N. Hough. It was known to Por- 

 chinsky in Russia as a dung feeder although the kind of dung is 

 not mentioned by Osten Sacken in his abstract of the Russian 

 writer's paper. It lays not more than 24 large eggs which hatch 

 in 24 hours. The larval period is of brief duration. 



It was reared at Washington in nine specimens on May 30 

 from human fasces deposited May 12, 1899, and eight additional 

 specimens issued on June 2. It was formerly reared on May 



Fig. 26. Myospila tneditabunda : adult — enlarged (original). 



27 from deposits which had been exposed earlier in the month. 

 It also issued on June 5 from twelve-day-old fteces, additional 

 specimens issuing on the 6th from the same deposit. The mini- 

 mum duration of a generation is thus 12 days. It was captured 

 upon excrement at Travilah, Maryland, July 5, and several 

 times at Washington, District of Columbia, and at Twining 

 City, Maryland, in June. 



Stoinoxys calcitrans Linn. 

 This fly, common to Europe and North America, has a very 

 wide distribution and is a well-known biting fly ; it was prob- 

 ably introduced into this country from Europe at an early date. 

 The larv£e live in fresh horse manure and the flies live chiefly 



