698 Coleopferological Notices, IV. 



PEBTTARTHRIIVUS n. gen. 



I refer to this genus several species which have been previously 

 assigned to Amaurorhinus Fairm. Amaurorhinus, according to 

 Wollaston, has the scutellum obsolete, the eyes rudimentary or 

 obsolete, the elytra oval or fusiform, the antenna? inserted far 

 beyond the middle of the beak, and the metasternum short, all of 

 which characters are at variance with the species under considera- 

 tion. As represented by the four species in my cabinet, Pentar- 

 thrinus may be known by the following characters: — 



Body feebly snbcmieiform, moderately convex, polished and glabrous, with 

 the scutellura distinct, metasternum elongate, anterior coxse approximate, and ' 

 the intermediate separated by much less than their own width. Beak very 

 short, thick, parallel, longitudinally convex, separated from the head by a 

 very broad transverse impression. Eyes well developed, moderately convex, 

 at the sides of the head, distant from the prothorax and finely faceted. 

 Antennae inserted at basal third, in deep wide scrobes which are horizontal 

 nearly to the margin of the eye, then dilated or flexed downward ; scape short, 

 thick; funicle 5-jointed, the basal joint large, the others subequal in length, 

 obconical, wider than long, the articulations distinct; club abrupt. Legs 

 short and slender, the tarsi slender with the third joint but slightly dilated. 



Pentarthrinus is quite closely related to Pentarthrum and Pseu- 

 dopentarthrum, but differs from the former in the more approximate 

 anterior coxae, and from the latter in the abrupt antenual club. The 

 species may be separated as follows: — 



Anterior coxse extremely approximate but not in actual contact; beak not 

 impressed in basal half. 

 Pronotum rather coarsely deeply and conspicuously punctate, with the 

 interspaces highly polished. 

 Elytral intervals twice as wide as the strife, flat, minutely, very sparsely 



and somewhat confusedly punctate in single series Ilitens 



Elytral intervals narrow, not wider than the striae, each with a single 

 series of fine but distinct punctures, more oi- less confused on the sutural 



interval ; pi-othorax small parvicollis 



Pronotum slightly alutaceous, sparsely, less deeply and much more finely 

 punctate ; elytral intervals narrow, polished, strongly convex, with the 

 punctures of the single series remote, excessively minute and scarcely 



discernable , piceus 



Anterior coxae narrowly though quite perceptibly separated ; beak narrowly 

 impressed along the median line in basal half or more atrolucens 



P. nitens Horn — Proc. Am. Phil. Soc, XIII, 1S73, p. 434 (Amaurorhinus ?). 



Subcylindrical or feebly cuneate, moderately convex, just visibly 

 wider behind the middle of the elytra, polished, black and glabrous 

 throughout. Head finely, sparsely, the beak equally finely but more 



