COLEOPTEROUS INSECTS. 
Ill 
the joints is most commonly triangular or elongate- 
quadrate. On the under side they are usually densely 
clofchecUwith hairs or bristles forming a kind of cush- 
ion, which enables the insects to make their footing 
more secure. The tarsi terminate in two curved 
claws, which in some instances are double, and in 
others are bifid at the tip. They are frequently 
serrated on the under side. 
As the anterior pair of legs are in most cases con- 
vertible into organs of prehension, they sometimes 
exhibit striking peculiarities in their structure in 
order to adapt them to this usage. In several 
species they are remarkably elongated, and occa- 
sionally provided with a kind of hook at the extre- 
mity of the tibia, as in the harlequin beetle, repre- 
sented on Plate XXV. In other instances, as among 
some of the predacious Carabid<c> the anterior ti- 
biae have a deep notch on the inner side towards 
the apex, above which there is placed a strong 
moveable spine, w r hich admits of being pressed 
down across the opening, and thus secures any 
object that may happen to be within it. A scarce 
British beetle, found on the coast of Norfolk, and 
on the shores of the Frith of Forth near Portobello 
( Cillenum laterale), shows an arrangement of this 
kind ; and it is rendered still more efficient by the 
addition of tw o small spines on the side of the notch 
opposite to the moveable spine, which receive the 
latter between them when it closes, and prevent it 
from being twisted in a lateral direction (fig. 1 of the 
