Genera of the Cossonida. 557 



67. MEGALOCORYNUS (nov. 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 every 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 Cos sonus. 



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 twisted 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 

 flattened, 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 small 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 coxas (even the front ones) are exceedingly remote. Its 

 antennas 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. CATOLETHRUS (Schonherr, Gen. et Spec. Cure. iv. 

 1077. 1838). The genus Catolethrus is composed of 

 a few elongated (occasionally minute), narrow, somewhat 

 shining, depressed Cossonus-like 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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