256 MEMOIRS ON THE COLEOPTERA 



converging for about half the length, thence broadly rounding to the 

 apex, finely margined; surface with fine sparse punctures, becoming 

 rather coarse and close toward the sides and fine again narrowly along 

 the margin; scutellum very small, elongate and sharply angulate; elytra 

 two-thirds longer than the prothorax, only slightly abbreviated, feebly 

 dilated near the base, with rounded sides, the four discal striae coarse, 

 extending far behind the middle, the outer subhumeral effaced, the inner 

 distinct from the end of the ruguliform oblique humeral, which is parallel 

 to the outer dorsal, to about apical third; sutural stria extremely short, 

 basal; surface with rather close-set, moderate punctures, becoming fine 

 and sparse suturo-basally, the discal striae continued posteriorly by 

 punctureless lines; prosternal striae obliquely converging in front and 

 united at apex as usual, the surface feebly convex, almost smooth, the 

 arcuate base fitting against the broad mesosternal sinuation; meta- 

 sternum strongly punctate like the mesosternum, the former puncture- 

 less medially; meso-metasternal suture distinct, crenate; anterior tibiae 

 with only four or five external denticles apically, all feeble except the 

 subapical. Length 2.5 mm.; width 1.68 mm. District of Columbia. 



This species is distinguished particularly by the form and sculp- 

 ture of the pygidium, which is convex, very slightly longer than wide, 

 with coarse and very close, strongly umbilicate punctures, which, 

 apically, become less coarse, transversely linear and arranged con- 

 centrically about the centre of the unmodified, bluntly angulate 

 and less convex apex. No other species known to me has pygidial 

 characters of this kind, or at any rate developed to this degree. 



Gnathoncus ovulatus n. sp. Similarly much stouter than in deletus, 

 rather convex, shining, black, the pygidium and legs obscure rufous; 

 head minutely, sparsely punctate; prothorax distinctly less than twice 

 as wide as long, much longer than in the preceding and with the sparse 

 punctures more evenly distributed, a little stronger and less sparse 

 laterally, the fine marginal line not quite reaching the base; sides moder- 

 ately converging to rather beyond the middle, thence broadly rounding 

 to the apex, but less strongly than in the preceding species; scutellum 

 minute, acute, less elongate than in the preceding; elytra nearly as in 

 the preceding and also inflated basally, but less narrowed behind and 

 with broader apex, the punctures much finer and sparser, gradually be- 

 coming wholly obsolete medio-basally ; the four discal striae are coarse, 

 subequal and extend to distinctly behind the middle, not continued by 

 punctureless streaks, the outer subhumeral fine but distinct in basal 

 fifth, the inner very fine, oblique from near the middle to apical third, 

 the oblique humeral fine, subparallel, the sutural limited to the narrow 

 basal arcuation, the intermediate arc clearly isolated; pygidium convex, 

 polished, barely longer than wide, the transverse umbilicate punctures 

 smaller and less close than in idiopygus, irregularly confused apically; 

 sterna nearly similar, except that the mesosternum is less abbreviated 

 and much more sparsely punctate, with the suture more feebly and 



