Genera of the Cossonidce. 557 
67. Megalocorynus {?iov. gen.). — It is for the Cos- 
sonus depressus and conicirostris, of Boheman, and a 
closely allied species (or perhaps only local variety) which 
has been communicated by Mr. Janson, all of them from 
Mexico, that the present genus is proposed ; and, apart 
from eveiy other character, they may be immediately dis- 
tinguished from the Cossoni, not only by their largely- 
developed club, but by the sexual disparity in the structure 
of their rostrum and antennae, — in both of which respects 
indeed, no less than in their more evenly and densely punc- 
tured prothorax, they are far nearer, in reality, to the 
groups around Mesites than to Cossonus. 
Not to mention its parallel and extremely flattened body, 
Megalocorynus is at once remarkable for the enormous 
size and length of its capitulum — which is parallel-oblong, 
and densely clothed with a velvety pubescence ; and its 
scape is peculiar from being somewhat ticisted and sub- 
compressed, — the inner edge (on account of the abrupt, 
but elongate, apical clavation) seeming to be almost 
scooped-out, or at any rate sinuated, posteriorly. Its 
rostrum, too, in the female sex, is of a very unusual 
shape, — being rather short and narrow, but nevertheless 
Jiattened, and gradually a little contracted towards the 
base ; whilst in the males it is longer, and dilated ante- 
riorly much after the fashion of the ordinary Cossoni. 
Its eyes (instead of being transverse) are nearly round ; 
its prothorax is somewhat smaU and abbreviated, and a 
good deal rounded at the sides ; its elytra (which are 
appreciably wider than the prothorax) are parallel and 
deeply sculptured, with the interstices almost costate ; and 
its coxfB (even the front ones) are exceedingly remote. Its 
antennae in the male sex are inserted a long way before, 
but in the females a long way behind, the middle of the 
rostrum ; and they are likewise longer and more robust in 
the former case than in the latter, and have their scape 
more conspicuously clavate, and their capitulum, if any- 
thing, even still more developed. 
68. Catoletpirus (Schonherr, Gen. et Spec. Cure. iv. 
1077. 1838). — The genus Catolethrus is composed of 
a few elongated (occasionally minute), narrow, somewhat 
shining, depressed Cosso7ius-\\\ie insects, of which the 
main distinguishing features seem to consist, so far at 
least as I am able to detect them, in their rostrum being 
(especially in the female sex) rather elongate and slender, 
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