XXX 
JOURNAL OF PROCEEDINGS. 
M. Theodore Lacordaire, Professor of Natural History at Liege, 
was elected an Ordinary Member of the Society. 
Exhibitions, Memoirs, &c. 
Mr. Yarrell exhibited specimens of Agrotis segetis, which had 
been forwarded to him from Saffron Walden, where they have 
been very destructive to the turnips ; five or six attacking the roots 
of that and other kinds of plants. Mr. Scales also exhibited larvae 
of apparently the same insect, which had been equally destructive 
in his garden at Stoke Newington, the caterpillars coming abroad 
at night, and eating round the roots and vegetables just at the sur- 
face of the ground. 
The president exhibited a collection of the native Trilobites, upon 
which he made some remarks, announcing his intention of under- 
taking a memoir upon that tribe of extinct animals, and requesting 
the communication of specimens from the members. 
Mr. Westwood, on behalf of Mr. Sells, exhibited specimens of 
Chartergus nidulans, and its parasite Chalcis pyramided, Fab. several 
dead specimens of which latter Mr. Sells had obtained from a nest 
of the Chartergus. The secretary also exhibited a nest of this in- 
sect, and made some observations on the manner in which it was in- 
creased in size from time to time, as the community increased in ex- 
tent, fresh layers of cells being added at the under-side of the lower 
part of the nest, as was evident from a transverse section of the nest, 
and from each of the superior layers having a single circular orifice 
in the centre, as is also the case with the ordinary bottom of the nest, 
lie also presented a figure, and read some notes upon the specific 
characters of Chalcis pyramided. 
He also exhibited an original letter from the younger Linnaeus 
to Mr. Drury, giving an account, among other matters, of the 
habits of the CEstrus hominis, of South America. (This letter 
has been since published by Mr. Westwood, in the preface to 
the new edition of Drury’s Illustrations of Exotic Entomology.) 
He also made some observations upon the (apparently new) 
species of Aphis, found upon the plants of the West Indian nut 
grass, grown in the apartments of the Society, and which it was 
stated by Mr. J. C. Johnson, was an apparently unknown species 
of Cyperus, and which is very destructive in the West Indies, 
overrunning the cultivated grounds, so that it has been found 
necessary to offer rewards for the greatest number of the sifted 
roots. 
