NATURAL HISTORY SOCIETY OF GLASGOW. 295 



Mr Thomas Chapman exhibited the compound cocoon of Anaphe 

 reticuUda from Old Calabar, and remarked that this cocoon is 

 formed by a family of moths that are gregarious, and that feed 

 and spin in common, the specimen now shown being the result of 

 their united efforts. In external appearance it resembles a brown 

 sponge, and is about the size of a cocoa-nut compressed. It 

 differs from any compound cocoons found in this country in hav- 

 ing under the outward silky covering a tough envelope of the 

 consistency of parchment, which encloses the interior cocoons, and 

 being impervious to wet, must furnish a complete protection to 

 the inmates. Mr Chapman also showed a number of moths from 

 the same cocoon, which had emerged in Glasgow. It had unfor- 

 tunately been cut open after its arrival in this country, or many 

 more specimens might have been obtained, a considerable number 

 of the insects having died in consequence of the exposure. 



PAPERS READ. 



I. — On the habits of Nematus femoralis (Zaddach). By 

 Mr Peter Cameron, jun. 



If we compare the larvae of the gall-making Saw-flies with each 

 other, we will find that they divide themselves into two groups : 

 those composing the first group remaining of a white colour during 

 all their larval life ; while those belonging to the second division 

 are only white till they cease feeding, when they moult, and the 

 white colour gives place to slate or orange. The galls, again, are 

 divisible into three classes. First, those formed of enlarged 

 twigs — e.g., Nematus saliceti, Fall. ; second, of round, pea-shaped 

 galls, attached only by a small point to the under side of the leaf, 

 and usually of a green colour, with reddish cheeks — e.g., Nematus 

 cinerece ; and, third, of flat, bean-shaped galls, attached by their 

 whole surface to the leaf-blades — e.g., Nematus Vallisnieri. 



A good number of gall-making Tenthredinidae have been de- 

 scribed ; but the subject is still involved in considerable obscurity, 

 and the proper discrimination of the species is very difficult. It 

 is not easy to fix upon characters that do not vary ; and the 

 difficulty is increased by the fact that the larvae of even every 

 different and distinct species closely resemble one another, so 

 that comparatively little confidence can be placed in this usually 

 good means of separating closely allied forms. Nor do the galls 

 afford very reliable specific characters ; for the same insect does 



