Casey — Obiervations on the Staphylinidae. 373 



DiNOLiNUS n. gen. — This genus is founded upon the large 

 and brilliant blue-green polished species described by Erich- 

 son under the name Xantholinus chalybeus. The Mexican 

 examples before me do not depart enough from Erichson's 

 description of the Brazilian type to warrant separation with- 

 out actual comparison, although there are probably diver- 

 gencies of at least a varietal nature in a species of such wide 

 distribution. The genus Dinolinus will apparently include 

 also the Xantholinus rutilus of Perty. 



Saurohypnus Shp. — Although closely BXYxed to Eulissus^ 

 differing principally in the formation of the labrum and epi- 

 stoma, rather more widely separated antennae and system of 

 cephalic and elytral sculpture, it seems apparent that these 

 distinctive characters constitute a necessity for generic sepa- 

 ation. Saurohypnus is apparently confined to the elevated 

 regions of northern and central Mexico and is composed of 

 moderately large, slender and convex species. It is greatly 

 out of place in the systematic arrangement adopted in the 

 Biologia. The only species actually known to me in nature 

 may be described as follows : — 



Parallel, rather strongly convex, polished, black, the palpi, entire elytra, 

 apical half of the fifth and entire sixth ventrals, rufous, the legs and 

 antennae piceous-black with the tarsi pale; head large, oblong, behind 

 the aatennae but little longer than wide, parallel and nearly straight at 

 the sides, the basal angles broadly rounded; punctures rather coarse 

 and close-set throughout the upper surface, without an impunctate 

 median line and having a very large puncture above each eye; sides 

 wholly unmodified and evenly convex ; under surface rather coarsely, 

 moderately closely punctate throughout, the punctures — like those of 

 the upper surface — miogled with smaller punctures and somewhat 

 elongate in form; antennae but little longer than the head, the pennlti" 

 mate joint one-half wider than long; mandibles moderately thick, arcu- 

 ate, convex and wholly devoid of groove externally; prothorax two- 

 flfths longer than wide, four- fifths as wide as the head, the apical 

 angles scarcely at all rounded, the sides distinctly converging pos- 

 teriorly throughout, feebly sinuate behind the middle; disk having nu- 

 merous punctures toward the extreme lateral margins, a group of three 

 large punctures near each apical angle, from which several smaller ones 

 stream posteriorly in a short longitudinal line, and others scattered 

 along the oblique apical margins ; elytra longer than wide, parallel, as 

 long as the prothorax and distinctly wider but not quite as wide as the 

 head, the punctures distinct, rather close -set and only feebly sublinear 

 in arrangement throughout, with the usual smooth polished line along 



