EXTERNAL ANATOMY OF INSECTS. 541 
sometimes very wide in proportion to its length—Dyfis- 
cus, Heleus ; at others very long in proportion to its 
width—Colliuris, Brentus, Mantis, &c. In Flata, and 
many other Homopterous Hemiptera, it is extremely 
short ; extremely long in Gnoma ; in Sagra and Donacia 
its width about equals its length; in Elater, Dytiscus, and 
many Heteropterous Hemiptera, it is narrowest before; 
in Languria it is every where of equal width; in Anthia, 
Carabus, &c., it is widest before; and, lastly, in the 
Scarabeide it is usually widest in the middle. 
ii. Antepectus*.—The antepectus, as was before ob- 
served”, in some tribes forms one piece, without any 
kind of separation, with the prothorax ; but very often 
this is not the case. In the ground beetles (Euwtrechina) 
it occupies almost the whole under-side of the manitrunk ; 
but in L£later, in which the ora is very wide, the antepec- 
tus is merely the mzddle portion of that part. In Cara- 
bus, &c. between the ora and the base of the arms is a 
convex triangular piece, distinguished from the rest of 
the antepectus by a spurious suture; and in Pentatoma 
and other Heteropterous Hemiptera a similar piece is 
observable, which terminates in a convex bilobed sub- 
triangular sheath, receiving the base of the clavicle ¢. 
This piece seems a prop to that part, and analogous to 
the scapula of the medipectus and parapleura of the post- 
pectus. I shall say no more upon the antepectus, as it 
is seldom remarkable. In the mole-cricket, however, 
one peculiarity distinguishes it: it is in this of an elastic 
* Prate VIIL, 6. b See above, p. 534. 
* Something of the kind is observable at the base of the other 
legs in this tribe. 
