The Ohio ^JSCaturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State Uni'versity. 

 Volume VII. APRIL, 1907. No. 6 



TABLE OF CONTENTS. 



HiNE— Robber Flies of the Geuns Philonicus 115 



Stowe— Winter Key to Ohio Chestnuts 118 



Jackson, Mrs.— Xotes and Methods on Collecting and Preserving Thysanura 119 



Hawkins— The Development of the Sporangium of Equisetuni hyemalc 122 



ROBBER FLIES OF THE GENUS PHILONICUS. 



James S. Hine. 



Philonicus was proposed by Loew in Linnaea Entomologica, 

 Volume IV, page 144, to receive a single European species which 

 had been known under the name of Asilus albiceps. After 

 studying the last named European species carefully, I find that 

 ^ve have at least four distinct North American species which are 

 congeneric with it. Bellardi referred two Mexican species to 

 the genus, but Williston concludes that one of these belongs to 

 HeHgmoneura and has published the synonymy in Biologia 

 Centrali Americana. So the four species are made up of three 

 from the United States and one from Mexico. 



It appears that American authors have been misled by the 

 fact that Loew proposed Philodicus as a generic name in another 

 section of the same subfamily, thus giving two names so near 

 alike as to be easily confused. His description of the latter 

 genus is published in Linnaea Entomologica, Volume III, page 

 391. The singular thing about the matter is, that Loew himself 

 in Dipteren Fauna Sudafrika's, page 144, uses Philodicus 

 where he intended Philonicus, and I suspect this fact also has 

 proven a stumbling block to some students. 



So far as known at present there are no species of Philodicus 

 in North America, so the name is most likely misplaced when 

 used in reference to Nearctic Diptera. 



In his studies of European Asilinae Loew used many char- 

 acters taken from the oviduct; thus he separated the females 

 into two grotips, one in which the oviduct is conical and one in 

 which the oviduct is compressed. European species appear to 

 be separated readily by this character, but in our species, 

 especially after they are dry, some difficulties are encountered, 



