78 ENTOMOLOGICAL SOCIETY 



considerable humus ; and he drew attention to the futility of 

 attempting to base specific differences on structures of this kind, 

 which are so apt to be divergent, depending on the surrounding 

 conditions, the same species adapting itself to changed environ 

 ment and constructing widely different structures. 



Dr. Marx said that if ant-feeding insects were included in 

 mrymecophilous species, the large Arachnid, Solpugo, should 

 be classed among them. He described its method of feeding on 

 ants at some length, based on the observations of Mr. Gustav 

 Eisen in Lower California, and those of Mr. Caspar Butcher in 

 Texas. Mr. Schwarz stated that these Arachnids are abundant 

 in the West but are always nocturnal in habit, and observations 

 such as those described by Dr. Marx could be made only with 

 great difficulty. 



Mr. Marlatt presented the following paper : 



NEURATION OF THE WINGS OF TENTHREDINID^E. 

 By C. L. MARLATT. 



In the first study of any group of insects in which the neuration 

 plays an important part in classification, one is apt to be dis 

 couraged by the varied and conflicting terminology of the veins 

 and cells, in the description of which scarcely any two authors 

 agree. To increase the difficulty, it frequently happens that an 

 author's system has to be picked up from random descriptions 

 without the aid of any full and adequate explanation in connection 

 with figures. These last, also, are absolutely necessary to the 

 correct understanding of the names, because of the frequent use 

 of the same terms for distinct things by different writers. 



Two of the later European writers on the Tenthredinidre, 

 Cameron and Andre, have, however, given very careful and full 

 explanations, leaving little to be desired in this respect, and have 

 practically coincided in a very satisfactory terminology which 

 harmonizes, also, as well as could be with older systems. Konow T 

 has given a rather imperfect explanation of the system which he 

 has followed, and which is based on that of the older German 

 authors. The importance of Konow's recent work in the Ten- 

 thredinidae gives value to certain features of this terminology, 

 which will be explained later on. 



The American writers have generally followed Norton and 

 Cresson, whose terminology, though good, lacks completeness, 

 and is at a disadvantage on account of its divergence from the 

 accepted system of Europeans. Still, if we had only to deal with 



