1849.] Linnean Society. io 



Society, who permitted him to make known the circumstance. The 

 author also corrected his view with regard to the nature of the food 

 of the larva of the second species he had discovered in the nest of 

 Anthophora, which he had named provisionally Monodontomerus 

 nitidus, but which is now believed to be Monodontomerus obsoletus, 

 which species had been suspected of infesting the genus Osmia, 

 although the larva had hitherto been unknown. Having carefully 

 examined the form of its mandibles since the first part of the paper 

 was read, he now finds that they are acute, slender, and fitted only 

 for piercing and not for comminuting food, and consequently he agrees 

 with Mr. Smith that the species is carnivorous, and not pollinivorous 

 as he had supposed. Further examination of this larva, therefore, 

 has tended to confirm the general views which he had maintained, 

 that structure when carefully and accurately investigated is an in- 

 fallible index to function and habits. 



The second part of the paper on the Ichneumonidee was then read. 

 This comprised a detailed account of the natural history of Paniscus 

 virgatus from the bursting of the ovum to the assumption of the 

 imago state. The egg, as noticed by Uegeer in Ophion luteum, and 

 by Hartig in other species, is affixed by a pedicle to the skin of the 

 caterpillar on which the larva is destined to feed, and the larva con- 

 tinues attached to it during the whole period of growth. Mr. New- 

 port found the eggs of Paniscus virgatus on the full-grown larva of 

 the broom-moth, Mamestra pisi, on the 26th of September 1847. 

 They were black, shining, and of a pear- shaped form, and each was 

 attached by a pedicle inserted into the skin of the caterpillar. At 

 the moment of being hatched they were burst in front, by a vertical 

 fissure, like the eggs of the lulidce, and the head only of the larva 

 was gradually protruded, so that at first these ova more resembled 

 the growing seeds of leguminous plants than animal organisms. 

 'Hie anterior portion only of the body was afterwards slowly pro- 

 truded, but the larvae gave no evidence of sensation during the whole 

 of their growth, and scarcely even of vitality. Yet affixed by one 

 extremity to the shell, and by the mouth to the skin of the cater- 

 pillar, they grew rapidly until at from the 12th to the 15th day they 

 had acquired their full size, and measured half an inch in length, and 

 then for the first time became detached from the shell. The author 

 then described the form and motions of the stomach as seen through 

 the tegument on the second day of growth, and also the structure 

 of the head, the distribution of the tracheae, and the mode in which 

 the larva changes its skin while still attached to the egg-shell. This 

 change was now seen for the first time in the apodal larvae of Hyme- 



