232 THE KNTOMOLOGIST. 



containing many very rare species arranged with the silk they produce, 

 the whole forming an educational exhibit of exceeding interest. 



The concluding meeting of the session was held on April 9th, Mr. 

 Geo. Arnold, Vice President, in the chair. — Mr. Wm. Mansbridge gave 

 an address on GnipJiolitha ncevana and G. ('? var.) geminana, in which 

 he dealt with the various forms of these insects in Lancashire and 

 Yorkshire. He stated that in the West Riding the two species were 

 in the imago state at the same time in localities near to one another, 

 where the holly form {ncBvana) and the bilberry form {(jeminaua) oc- 

 curred. At Delamere however the bilberry feeder was worn at the 

 time the holly feeder was beginning to emerge in the district around 

 Liverpool. Although ncevana from holly had a variation like geminana, 

 it was never so pale as the latter, and the moth from bilberry was al- 

 ways smaller in size ; geminana did not possess a black variation like 

 ncBvana, but a very small percentage were unicolorous dark grey. — Mr. 

 F. N. Pierce then described the results of his examination of the 

 genitalia of the two species ; after critically comparing a long series 

 of preparations of both males and females he had failed to distinguish 

 any point of difference. In discussion by the members it was held 

 that the negative character of Mr. Pierce's results was not sufficient, 

 in this instance, to sink geminana to the level of a variation of 

 ncEvana. — Mr. Wm. Mansbridge "exhibited a long series of Selenia 

 bilunaria, comprising very dark speckled forms, and a new variation 

 of a uniform dark ferruginous brown colour for which he proposed the 

 varietal name bnmnearia. Mr. C. E. Stott showed a specimen of 

 Panchlora nivea, L., an exotic cockroach, taken on the wing at 

 Trentham, North Stafford, in October, 1910.— H. R. Sweeting and 

 Wm. Mansbridge, Hon. Sees. 



RECENT LITERATURE. 



Fossil Insects and a Critstacean from Florissant, Colorado. By 



T. D. A. CocKEEELL. (Author's edition, extracted from 



' Bulletin ' of the American Museum of Natural History. Vol. 



xxviii. art. xxv. pp. 275-288. New York : October 19th, 1910.) 



Includes descriptions of two new species of Trichoptera, four of 



Hymenoptera, and six of Diptera. 



The Thorax of the Hymenoptera. By Robert Evans Snodgrass. 

 No. 1774. From the 'Proceedings' of the United States 

 National Museum. Vol. xxxix. Pp. 37-91, with plates 1-16. 

 Published October 25th, 1910. 

 In this paper the external morphology of the thorax of the non- 

 aculeate Hymenoptera is discussed and illustrated. As we under- 

 stand the author, classification should not be based on thoracic 

 structure alone, but on a study of the structure of all the parts of the 

 body. Any system of taxinomy or phylogeny, he states, must be 

 founded on a consideration of all the characters of all the forms 

 concerned. 



