146 ENTOMOLOGICAL NEWS. [June, 



else formed by the fusion of a number of hairs into a flat plate. 

 The writer would suggest for these structures an auditory func- 

 tion. Those of P. olympia are admirably adapted for this pur- 

 pose, as on each joint the four processes are so arranged that 

 each would take up a vibration from a different direction while 

 the others would not be disturbed, which would enable the 

 animal to detect not only sound, but its direction. 



So far as observed the Psychodids are never captured in spiders' 

 webs and this is explained, the writer believes, by the density and 

 peculiar arrangement of the hairs upon the body, and especially 

 upon the legs. The little flies may often be seen calmly walking 

 over the snares so fatal to almost the whole race of Diptera and 

 if they come in contact with the webs in their flight they are 

 never more than temporarily embarrassed. 



-o- 



A PRELIMINARY CLASSIFICATION OF THE SPECIES OF THE 

 GENUS ACRONYCTA OF TEMPERATE NORTH AMERICA. 



By JOHN B. SMITH, Sc. D. 



For some months past I have been engaged in a monographic 

 revision of the genus Acronyda as represented in our fauna, and 

 have been assisted in this work, so far as the early stages are 

 concerned, by Dr. H. G. Dyar. The preliminary arrangement 

 is now completed, and the new species have been determined, but 

 it will be weeks before the mss. is in final shape for publication, 

 and months before it can be actually printed. Inasmuch as there 

 are quite a number of species represented in several collections, 

 to which mss. names must be attached when they are returned 

 to those who kindly loaned them to me, I have considered it best 

 to present synoptic tables of all the species, indicating those that 

 are new and differentiating them from their nearest allies. This 

 will give validity to the names attached to the specimens and will 

 not anticipate the full discussion of their structural and other 

 characters in the monograph. The preliminary division of the 

 genus into groups may not be entirely clear without the explana- 

 tory discussion, but can be made so by any one who will arrange 

 his species in the series and will study the sexual characters of 

 any one species of each group. It may be said that the order 

 of the species in the tables is arbitrary, for convenience in iden- 



