166 MESSRS. C. HORNE AND F. SMITH ON HYMENOPTERA 
Fam. EUMENIDA. 
Eumenss conica, Fabr. (Plate XX. figs. 2 & 2 a.) 
As I bred many of these insects, I had ample opportunity of watching them. They 
place their nests on the walls of houses, but prefer wood, such as door-frames; while 
sometimes they make series of cells of great length, one such series often extending 
more than one foot. 
One pair of insects will construct twelve or thirteen cells, and it does not take an 
entire day to complete one of them; yet I have often thought I could detect more than 
one pair engaged in one place, but at different ends of the structure, which, when com- 
pleted, contained perhaps twenty-four cells. 
It should be remembered that the insect avails itself of the wall or beam for the back 
of its cell, which is made extremely thin, the clay which is carried beneath the mouth 
being beautifully fine and well kneaded. Hence it is extremely difficult to detach their 
cells without breaking them. The cells are high and vaulted, and at the mouth they 
have a protruding rim, which projects outward and curves slightly downward. ‘Ten or 
twelve green caterpillars are stored in each cell, which is carefully closed with mud. 
This insect, like Pelopaus madraspatanus, seems very proud of its work, and, before 
leaving for fresh material, runs about approvingly and thoroughly inspects its perform- 
ance. If disturbed it flies off, and does not attack you as do the Vespide. 
The imago generally emerges about five weeks after the cell has been closed; and, 
owing to the thinness of the walls, which are easily pierced, it is much attacked by 
parasites. ‘Thus out of one group of five cells, only two specimens of Humenes were 
hatched. Of these parasites I shall speak afterwards. 
In life the Zwmenes is much brighter in colour than it becomes after death, so that 
no idea of its beauty when at work can be readily formed from the specimens. It was 
from one of the cells of this species that I took nine caterpillars, eight of them being 
black Geometers, and only one green one; so that it is clear the insect had, contrary to 
custom, met with a brood of another colour which suited it quite as well as the green, 
which it generally uses. 
EUMENES ESURIENS, Fabr. (Plate XX. figs. 6 & 6a.) 
This beautiful insect builds its cells about doors and windows, on the posts; and fig. 6 
may be held to be a typical structure. As, however, I bred them from cells of different 
forms, there can be no doubt that they vary their style with the site. The cells are high, 
very spherical, and placed generally irregularly. Green caterpillars (chiefly Geometers) 
are stowed away, whilst one often finds the cells in the possession of a Golden Wasp 
(Chrysis), a parasite. The mouth of the cell resembles that of the other species in 
having a recurved lip, this being characteristic of this group. The reason why so many 
cells are empty after the escape of the perfect insect is, that the ants come in troops 
