306 CURCULIOXID.^. 



[LeConte. 



One specimen, collected by me near the Rocky Mountains. The scales 

 are partly abraded; on the elytra they remain only at the base and near the 

 extremity of the fourth to the seventh interspaces. 



CENTRINUS Sell. 



After separating a certain number of species, wliicli seem to indicate 

 distinct and well defined genera, there remains a tolerably numerous mass, 

 which, although not entirely homogeneous, consists of species having in 

 common the following characters. The study of foreign species may per- 

 mit at a future time a fiirther subdivision, but the transition between the 

 extreme forms seems so gradual, that I am unwilling, with my present 

 knowledge, to indicate the 'manner in which this may be effected. 



The beak is long and slender, cylindrical, and usually curved, but some- 

 times nearly straight; tlie antenna! grooves commence about the middle, 

 descend obliquely, and are wider, deeper and confluent behind. Mandi- 

 bles small, flattened, pointed, prominent, and without teeth. Antenna; 

 rather slender, funicle 7-jointed, joints 1-3 varj'ing in length, 4-7 equal 

 in lengtli, not passing into the club, which is oval, somewhat pointed, pu- 

 bescent and annulated. Prothorax narrowed and more or less constricted 

 in front, without postocular lobes; prosternum long in front of the coxa?, 

 which are rather widely separated; not emarginate in front, impressed or 

 not, according to species. Elytra sometimes elongate with parallel sides, 

 though usually narrowed from the humeri, so as to give a rhoniboidal form 

 of body; posterior callosity feeble, tips usually conjointly rounded, some- 

 times separately rounded, exposing in the latter case a small part of the 

 pygidium, which is, however, horizontal, and not vertical, as in Ban's and 

 its allies. The middle and hind coxse are widely separated; metasternuni 

 rather short, with wide episterna in the rhoniboidal species; longer, with 

 narrower episterna in the elongate species; but in both cases distinctly 

 wider liefore and behind. Ventral surface ascending in some species, 

 nciU'ly horizontal in others; first and second joints longer than thii'd and 

 fourth ; fifth sometimes longer, sometimes not longer than the fourth ; 

 first suture subsinuate, the others strongly angulated at the sides. 

 Thighs unarmed, tibioe not striate on the outer side, very feebly mncronate 

 at tip; tarsi with the third joint very broad, bilobed, last joint long, with 

 stout, divergent claAvs. 



In the males of several species the prosternum just in front of the coxa? is 

 armed with a slender process, which varies in length according to the in- 

 dividual, but not according to species. 



A. Ehira separately strongly rounded at tip; pygidium partly exposed; 

 posterior edge of pi-othorax deeply emarginate beneath in front of 

 niesosternum. 

 Black, densely punctured ; above pruinose, 

 with fine scales or hairs, beneath scaly; 

 scutellum clothed with white scales 1. scutellutn-album. 



