TRIBE V. RHYNCOLINI. 541 



IV. PENTARTHRINUS Casey, 1892. (Gr., "five" + "joints.") 



Body subcylindrical or feebly wedge-shaped, convex, glabrous; 

 beak short, thick, parallel, separated from the head by a broad 

 shallow transverse impression ; eyes convex, distant from the 

 thorax, finely granulated; antenna? inserted at basal third, their 

 grooves dee]), wide, horizontal almost to eye, then dilated and 

 bent downwards; funicle 5-jointed, basal joint large, the others 

 obconical, subeqnal, wider than long; scutellum distinct; ninth 

 and tenth elytral stride united behind the humeri ; front coxa? very 

 narrowly separated ; legs short, tarsi slender. This genus is said 

 in Biologia to be doubtfully distinct from the preceding, but 

 Casey states that Pseudopentarthrum differs in its relatively 

 larger thorax, greater distance between the antennal grooves and 

 eyes, more compact and compressed antenna?, less abrupt club 

 and stouter legs. All the known species occur in our territory. 



KEY TO SPECIES OF PENTARTHRINUS. 



a. Front coxae almost contiguous but not in actual contact; beak not 



impressed in basal half. 



ft. Thorax rather coarsely, deeply and conspicuously punctate, the in- 

 terspaces between the punctures highly polished. 

 c. Elytral intervals twice as wide as striae, flat, each with an ir- 

 regular row of very sparse, minute punctures. 848. NITENS. 

 cc. Elytral intervals narrow, not wider than striae, each with a sin- 

 gle row of fine but distinct punctures, more or less confused 

 on the siitural interval. 849. PAKVICOLTJS. 



~bb. Thorax finely alutaceous, sparsely, less deeply and much more 

 finely punctate; elytral intervals very narrow, polished, strongly 

 convex, the punctures of the single row remote, very minute. 



850. PICEUS. 

 oa. Front coxa? narrowly though quite evidently separated. 



(1. Beak narrowly impressed along the median line in basal half or 



more: elytral striae feebly impressed, their intervals flat, as wide 



as striae. 851. ATROLUCENS. 



eld. Beak not impressed; striae deep, their intervals very narrow, convex. 



852. ANONUS. 



848 (9040). PENTARTHRINUS NITENS Horn, 1873, 434. 



Black, shining. Beak half as long as thorax, finely punctured, its 

 basal impression with a rather deep fovea. Thorax as wide as long, oval, 

 base slightly wider than apex, sides broadly curved from near the base; 

 disc moderately convex, coarsely, evenly, not densely punctured. Scutellum 

 small, smooth. Elytra oblong, one-fourth wider than thorax, sides feebly 

 curved; disc slightly broader behind the middle, constricted near apex; 

 striae feebly impressed, rather coarsely and closely punctured; intervals as 

 in key. Body beneath shining, coarsely and sparsely punctured, abdomen 

 more finely punctured. Length 2.5 3.3 mm. 



