256 Mr. J. O. Westwood on the Economy 
XL. On the Economy of the Genus Palmon of Dalman, 
with Descriptions of several Species belonging thereto. 
By J. O. Westwoop, F.LS., &e. 
[Read 5th March, 1844,] 
Ar the meeting of the Linnzan Society on the 6th February last, 
a very interesting paper was read by J. Curtis, Esq., F.L.S., con- 
taining descriptions of two singular nests of Hymenopterous 
insects, which he had recently Wnewed from Brazil: one of them 
consisted of a very numerous assemblage of the cocoons of a 
Tenthredinideous insect so closely packed together that when 
transversely cut the mass had very much the appearance of a piece 
of honeycomb, many of the cells being hexagonal, pentagonal, 
&c.; the whole was enclosed in a thick cottony covering, evi- 
dently spun by the larvee in common, previous to the Sarniion of 
the cocoons; and Mr. Curtis was led to believe that the object of 
this covering was to prevent Jchneumon flies, of which there is a 
vast number of species in Brazil, from depositing their eggs in the 
cocoons enclosed within, The great resemblance which exists 
between the appearance of the mass of cocoons described by Mr. 
Curtis and the masses of eggs of the Mantide, at once called to 
my mind some insects in my collection which at once disproved 
this suggestion of Mr. Curtis; and as they belong to a genus to 
whose history some interest is attached, I beg leave to offer the 
following remarks upon, and descriptions of them to the Entomo- 
logical Society. 
The instinct by which the females of the parasitic families 
Ichneumonide, Chalcidide and Proctotrupide are taught to deposit 
their eggs in the most seemingly secure retreats of their prey, is 
one of ‘the greatest interest. That species of Chalcidide, for 
instance, not possessing exserted ovipositors, should be enabled to 
detect their prey and penetrate the thick solid galls of the willow 
leaf or the hard egg-cases of the Blatte, is not more worthy of 
attention than that other species possessing long exserted but 
extremely delicate ovipositors should be able to penetrate the 
woolly bedeguar or the thick flossy outer covering of the eggs of 
the Mantide, and yet all these circumstances take place. 
In addition to a short notice by myself in the second volume of 
my “ Modern Classification of Insects,” the only statement I have 
hitherto met with respecting the last mentioned circumstance is 
