Vol. Xxix] ENTOMOLOGICAL NEWS. 145 



From the standpoint of numbers, the comparatively small 

 representation of Musca domcstica was most interesting-. It 

 constituted but 9.03 per cent, of the total catch. Muscina sta- 

 bnlans (Fallen) was unexpectedly abundant (16.27 P er cent, 

 of the total). This is a fact of some importance because there 

 are seasons of the year when this fly is almost the only one 

 found in houses. The same applies to Phorinia tcrrae novae 

 Desvoidy, which is one of the first flies found in house-; in the 

 spring, preceding the species just mentioned. The observa- 

 tions concerning these two species were made under rural 

 conditions. These flies, however, together with Phormia re- 

 gina (Meigen) and species of Calliphora, which appear later 

 in the season, do not seem to frequent food to any great ex- 

 tent when in-doors, but are most commonly seen on the win- 

 dows. The species of Fannia, of which F. scalans Fabricius 

 was, predominant, were the most abundant of the privy flies, 

 possibly because the species just noted is such a prolific breed- 

 er in latrines. The two species of Sarcophagidae, Ravin in 

 pcniculata R. Parker and Sarcophaga haemorrhoidalis Fallen, 

 both excreta breeders, were present in less number than 5". 

 coolcyi R. Parker, which breeds in carrion and decomposing 

 animal matter. It should be remembered in discussing these 

 figures that they represent the fly fauna for only a small part 

 of the fly season. At an earlier or a later period the compara- 

 tive abundance might be entirely different, for example, 

 Musca domcstica would be practically absent in the spring, 

 while Muscina stabulans would be likely to be more numerous. 

 Similarly the species of blow-flies vary greatly in comparative 

 numbers at different seasons. 



For the purposes of comparison a list of the species reared 

 from material from this same vault during the period of the 

 experiment are given: Fannia scalaris, Ophyra Icucostoma, 

 Limosina sp., Rhcgmoclcma atrata, and Ncmopoda cvlindrica. 

 Other species reared from material taken from deep vaults 

 were Dcsinametopa latipcs and Lcria scrrata ( Powderville. 

 Montana, 1916). There is a considerable difference between 

 species breeding in deep vaults and those breeding in surface 

 privies and in excrement dropped in the open. This the writrr 

 plans to discuss in another paper. 



Besides the Diptera, as noted above, a number of Lepidop- 

 tera, Orthoptera and Coleoptera, as well as numerous Ara- 

 neida and Phalangida were found in the Hodge traps. 



It is interesting to compare the data as given for the privy 

 trap experiment with the comparative percentages of some <>i" 

 the same species when trapped out-of-doors with human ex- 



