Linnean Society. 200 
that the extremity, which is free and usually round or somewhat 
pointed, can be slightly elevated, depressed, extended, retracted and 
moved laterally at will; and mentions that Professor Owen has de- 
tected a rudimental labrum in spiders of the genus Mygale. To 
apply the term mandibles to organs originating above the labrum, 
and therefore not situated within the mouth, is evidently erroneous ; 
and the author ventures to anticipate, upon anatomical consider. 
ations, that future investigations will lead to the conclusion that the 
mandibles of the Araneidea are confluent with the palate. 
March 6, 1849.—R. Brown, Esq., V.P., in the Chair. 
The necessary business of the Meeting having been disposed of, 
the Vice-President in the Chair proposed, that, in consequence of 
the recent death of Edward Forster, Esq., ‘Treasurer and Vice-Pre- 
sident of the Society, and in consideration of his long connexion 
with, and eminent services to, the Society and to Natural History, 
the Meeting should adjourn; which was unanimously agreed to. 
March 20.—The Lord Bishop of Norwich, President, in the Chair. 
Read a paper ‘‘ On the Anatomy and Development of certain Cha/- 
cidide and Ichneumonide, compared with their special economy and 
instincts ; with descriptions of a new genus and species of Bee Para- 
site.” Part I. By George Newport, Esq., F.R.S. & L.S. 
Mr. Newport remarked that the parasitic Hymenoptera in their 
larva state are among the most imperfectly organized forms of 
Articulata, and yet, having passed through this stage of their exist- 
ence, they become some of the more active and perfect of insects. 
They are nourished by suction, and either are attached singly to the 
external surface of the bodies of their victims, or reside in the same 
cells with them gregariously, or infest them internally, according to 
their species. In the whole of them, however, the general form of 
body and of the digestive organs, at the earlier periods of growth, is 
very similar, and the special development of each species is regulated 
by the same laws. ‘They cast their tegument at different periods of 
growth like other larvee, a fact which Mr. Newport has observed in 
Paniscus, although in the apodal larve of Hymenoptera it has 
heretofore escaped the observation of naturalists. Their digestive 
apparatus at first is extremely simple, and has the form of a capa- 
cious bag or sac, without any anal outlet. Consequently no feces 
are passed until the larvee have acquired their full growth and ceased 
to feed. After this period of assimilation the digestive cavity begins 
to assume a new condition. It becomes perforated at its base, and 
an intestine and anal outlet are formed, and feces are then passed. 
One reason for this late completion of the alimentary canal seems to 
be the necessity that the fluids of the insect preyed upon should be 
preserved in a healthy state for the support of the parasite; and 
another, that the food of the victim should not be contaminated. But 
when the parasites are full-grown the necessity for these conditions 
ceases, and the intestinal portion of the digestive apparatus is deve- 
loped. 
