18 BIOLOGICAL SURVEY OF 



The above numbers are based on species and varieties 

 actually taken on the island, with the exception of the Mal- 

 lophaga and two species of bird flies (Hippoboscidae). To 

 acquire actual records of these would necessitate the shoot- 

 ing of a large number of birds, the loss of which would not 

 compensate for the little knowledge gained. As over 80 per 

 cent of the birds are infested by these parasites, a list of the 

 species frequenting the more common birds of the island can 

 be depended upon to represent the approximate number of 

 species. 



Many groups like the Aphidae, Coccidae, and the host of 

 little parasitic Hymenoptera, especially the Chalcidoidea, re- 

 quiring special collecting and the work of specialists, have 

 not been studied. The Diptera, which have been more thor- 

 oughly studied than the other large orders, show to what 

 extent even Lower Austral species thrive in practically boreal 

 conditions. This applies, as I have already stated, more par- 

 ticularly to the maritime or halophilous species. The fol- 

 lowing species are all found in the salt marshes from Florida 

 to Mount Desert, and the range of some extends to Nova 

 Scotia: Aedes sollicitans, Tabanus nigrovittatus, CJirysops 

 fuliginosa, Odontomyia cincta, Chaetopsis aenea, C. apicalis, 

 Tetramerix unica, Phyllogaster cor dylur aides, Notiphila hi- 

 spinosa, Napaea imitans, and Dimecaena spinosa. Hoplo- 

 dictya setosa is found from Georgia to Mount Desert, while 

 many species common to the Upper Austral are also abundant 

 here. Bittacomorphella jonesii, described from Lake Toxo- 

 way. North Carolina, at an elevation of 3000 feet, is here 

 found at practically sea level — a distribution quite common 

 to many boreal species. In the Hymenoptera the large 

 number of Psammocharidae and Sphecidae give the fauna 

 quite an austral aspect. Vigorous flying moths like Aellopos 

 titans, etc., that are often carried by strong currents of air 

 far beyond their natural habitat, cannot be considered in de- 

 fining life zones. On the other hand, widely dispersed species 

 circumpolar in distribution are useful in defining the south- 

 ern limits of the boreal. To those especially interested in 

 distribution the list will show many noteworthy examples. 



