194 TRANSFORMATIONS OF INSECTS. 
HYMENOPTERA WITH DENSE INTEGUMENTS. 
(Chrysidide.) 
This family of Lymenoptera cannot be very readily associated 
with the others. The Chrystdide@ are commonly called ruby-tail 
flies or gilded wasps, and they have a close resemblance on 
account of their peculiar shape to tiny wasp-like flies, but they 
never attain a third of the size of the common Vespa. The bril- 
liant colours of the Chryszdid@ strike the observer at once, and 
their fiery tints look like a blaze of jewels. Some species have 
the body tinted with a beautiful golden green, others shine in 
ultramarine, and many have this splendid blue relieved by a 
scintillating ruby red colour on the abdomen. There are some 
large spots and chasings upon the thorax, which produce beautiful 
effects in the light, and thus the Chryszdid@ are splendid when 
moving restlessly here and there in the bright sunshine. Had 
they large bodies they would be prized for their beauty as the 
humming birds of the insect world, but as they are small crea- 
tures, their decorations are therefore less striking. 
The integuments of the Chrystdid@ are very thick and hard; 
and the insects have the power of rolling themselves up like a 
ball, by bringing the abdomen against the underneath part of the 
thorax. This is quite a peculiarity amongst these Hymenoptera ; 
moreover, they differ from others by having a cylindrical body, 
the abdomen being concave below, and very convex above, and 
attached to the thorax by a very short waist. The rings of the 
abdomen appear to shut up more or less within each other, like 
a telescope slide. The females carry a very sharp sting, which 
gives great pain. These insects have filiform antenne, long man- 
dibles ; the jaws have palpi, formed of five joints; and the lower 
lip projects, and is membranous, so that they can suck. The 
wings are moderately veined, and the legs are slender. These 
insects exhibit a wonderful amount of activity under a broiling 
sun, and then they are never still, but are constantly flying here 
and there, and resting a while upon the flowers. In some spots 
of central Europe—where these insects are much more common 
than in the north—they collect in numbers, and afford a mag- 
