128 
IIY MEN OUTERA. 
lustre. The wings have few veins, in some species they 
are absent. In some genera the femur of the hind-legs 
is enormously swollen, and sometimes internally ser¬ 
rated ; this thickening does not, however, as we might 
be inclined to think, indicate leaping powers. These 
insects are all parasitic upon others, chiefly in their 
larva and pupa states; some lay their eggs even within 
the eggs of other insects, and the larvm are nourished 
therein, which may give us some idea of their minute 
size. 
The Proctotrujridcc , like the preceding family, con¬ 
tains insects of very small size. A species of Platy- 
gaster is useful in checking the injury done to wheat 
by the two-winged insect, the Cecidomyia tritici. 
There are about four hundred British species in this 
family. 
We now come to the division of the Tubuliferw, so 
•called from the structure of the abdomen, the end of 
which is retractile like a telescope. The Ruby-tails 
(Chrysided) alone constitute this family, of which the 
common Chrysis ignita (Plate V., Fig. G) is a good 
representative. The brilliant colouring of this insect, 
with its head and thorax of metallic blue or green, and 
abdomen of crimson or fiery copper, has ivon it the 
name of the humming bird amongst insects. The 
Chrysis is parasitic in its habits, depositing its eggs 
within the cells of other Hymenopterous insects. The 
subject of the parasitism of the Chrysides has recently 
been investigated by Dr. Chapman (of Borghill, 
Hereford), who in conjunction with Mr. Steele of 
Abergaveny, lias published in the transactions of the 
Woolhope Naturalists’ Field Club, some very valuable 
