THE CANADIAN ENTOMOLOGIST. 215 



attack upon the shade trees of New York by P. cecropia was recorded; 

 and the suggestion made that this and other species might be turned to 

 account, if any means could be devised for manufacturing and utilizing 

 their silk. As a stimulus to this industry, Mr. Graef generously offered a 

 prize of fifty dollars for the best essay and model of apparatus for carrying 

 this suggestion into effect. 



Thursday, August 21st. — The Club met at 8 a. m. Dr. C. M. Weed 

 read an interesting paper upon the clover-stem borer, Languria mozardi. 

 Fifteen species of plants were reported upon which the larva had been 

 found feeding. This paper was discussed by Profs. Cook, Alwood, 

 Osborn and others. 



Prof Alwood spoke of tobacco insects, of which he was making a 

 special study. He had observed a stem borer which was very injurious. 



Dr. Weed had learned of a tobacco root-louse in Southern Ohio. 



Prof Garman spoke of the mouth parts of several species of some 

 families of Thysanoptera, and stated that some recent studies had shown 

 him that the figures published did not agree with his material. He then 

 read the following paper : — 



AN ASYMMETRY OF THE HEAD AND MOUTH PARTS OF THYSANOPTERA. 



In a brief paper in the Bulletin of the Essex Institute I have recently 

 called attention to peculiarities in the structure of the head and mouth 

 parts which set this group quite apart from other orders of Hexapoda. 

 [This has no reference to afifinities upon which, I believe, we are not pre- 

 pared to pronounce until this and several other groups have been more 

 completely studied.] In that paper it was claimed that the endocranium 

 of the species examined was not symmetrical, being deficient on the right 

 side ; that the labrum was one-sided ; that there was a developed mandi- 

 ble on the left side, with, at most, a rudiment on the right ; and that the 

 mandibles of authors were probably lobes of the maxillse. 



At the time the paper was written I had not examined sufficient ma- 

 terial to enable me to say whether the features pointed out were limited 

 to certain species or were common to all members of the group. Since 

 then many additional forms have been examined, all, however, belonging 

 to the families Stenopteridae and Coleoptratidge, and in no case has there 

 been found a departure in essentials from the structure of the head and 



