456 Mr. Westwoop on some new Species of Athyreus, 
ence may be placed on M. Lacordaire’s short statement. It is proper 
however not to overlook the evident resemblance which exists between the 
structure of the maxillae and mentum, &c. of Athyreus and that of several 
genera amongst the aberrant Trogide, of which I have published an ample 
analysis in the fourth volume of the * Transactions of the Entomological 
Society ;' in fact, so strong does this relation appear to me, that I have but 
little doubt that ultimately it will be found that the true relation of Athyreus 
is towards these aberrant Trogide. 
A few words are necessary with reference to those external characters in 
these insects which are to be considered as indicating the distinction of sex, 
and which, as in many of the Lamellicorn beetles, consist in tubercular or 
horny processes of the prothorax and head in the males, which are either 
obliterated or but very slightly developed in the opposite sex. It is to be 
regretted however that we possess very few positive indications in this mat- 
ter, and even here we find such a want of uniformity in the characters assigned 
to the distinction of sex in a few of the larger species, and such an apparent 
want of external sexual distinctions in some of the smaller species, that we 
are not yet able to speak with confidence on the subject, which is rendered 
still more difficult by the great rarity of the larger species. 
In some of the larger species the head of the male is elongated in front, 
the occiput terminating conically in a more or less elevated horn, the point 
of which extends over the labrum, and sometimes even reaches to a short 
distance in front of the head. The underside of this horn or tubercle is 
strictly formed of the clypeus. In the species which Dr. Klug has figured as 
Ath. bifurcatus, the conical clypeus reaches to the front of the labrum, termi- 
nating in a slightly-raised tubercle: the mandibles are very large and broad, 
extending beyond this point. The front of the prothorax is very retuse, and 
x furnished with two somewhat triangular tubercular processes of moderate 
size. The female of this species (which Dr. Burmeister has sent to Mr. Hope 
under the name of Ath. Surcicollis) has the head quite differently formed; — 
= occiput terminates in a transverse raised suture just in front of the inser- 
tion of the antenna, having its lateral angles and middle elevated into three 
small conical tubercles; beyond this appears the quadrate clypeus, the short _ 30 
labrum, and the smaller mandibles. (It is to be regretted that Dr. Klug has 
