36 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
the body blackish-green, while in chapuisi, there is not the slightest 
tinge of green on the underside. The species is not represented in 
the National Museum Collection, and it is placed in the key solely 
upon the characters given in the original description. 
PACHYSCHELUS UNICOLOR, new species. 
Male.—Subtrapeziformis, considerably longer than wide, strongly 
narrowed posteriorly, shining, glabrous, uniformly piceous, with a 
feeble violaceous reflection on the elytra; beneath piceous. 
Head strongly convex, feebly, longitudinally grooved from vertex 
to epistoma; surface sparsely, but distinctly punctate, and finely, 
densely granulated over entire surface. Pronotum moderately con- 
vex, not quite three times as wide as long at the middle, much nar- 
rower in front than behind, widest at base; sides strongly, obliquely 
arcuate from base to apical angles, which are rectangular; anterior 
margin broadly and rather deeply arcuately emarginate; base nearly 
truncate, abruptly sinuate at elytral lobes; hind angles acute, scarcely 
projecting beyond the humeral angles of the elytra and fitting closely 
to them; surface glabrous, rather densely punctate and finely, densely 
granulated at the sides, the punctures large and very shallow, be- 
coming obsolete on the disk. Scutellum smooth and glabrous, the 
anterior angles acute. Elytra as wide as pronotum at base; humeral 
angles obtusely rounded; sides obliquely attenuate from base to the 
tips, and slightly sinuate near the middle, tips conjointly broadly 
rounded, the lateral margin feebly serrate, and when viewed from 
the side is nearly straight, except for a slight sinuation for the posterior 
femora; each elytron with an obsolete depression at the base, and a 
broad, deep one along lateral margin behind the humerus; surface 
glabrous, sparsely and coarsely punctate, the punctures very shal- 
low on the disk, becoming feebly rugose in the humeral regions, the 
intervals rather smooth, becoming finely, densely granulated at the 
sides. Abdomen beneath strongly convex, sparsely and obsoletely 
punctate, with a few very short inconspicuous hairs; intervals finely 
and densely reticulate; last segment broadly rounded, with an ob- 
solete tooth at the tip, the portion in front of the marginal groove 
rather acutely angulated at apex. Elytralepipleura narrow. Meta- 
sternum more coarsely punctured than abdomen, and nearly trun- 
cate in front. Prosternum feebly, arcuately emarginate anteriorly; 
prosternal process about three times as wide as the coxal cavities; 
sides slightly expanded behind the coxae, and broadly rounded at 
apex; episternum short, flat, and triangular. Prothoracic epipleura 
wide and nearly flat, with a deep narrow groove behind the antennal 
groove; lateral margin rectangular; antennal groove deep, following 
the suture between the episternum and epipleura, extending into the 
latter to the tibial groove, and parallel to the lateral margin. 
