CERAMIiVClDAK. 219 



To Nothorhiua belongs Asernuni asjjeruvi Lcc, from Oix'oun 

 aud Vancouver. From Asemuin mubt be excluded A. am^lrule 

 hktc, vviiich is au anomalous Criocephalus, dilleriug IVoui all the 

 oliicrs by the eyes being deeply emarginale. 



Group II.— Opsimi. 



Opsimus quadrilinealus Mann., i'roin Alaska and Oregon, con- 

 stitutes this group; it is a lead-colored, finely i)ubescent insect, 

 having the prothorax armed with a lateral acute spine, and the 

 disk of the elytra with several vague impressions. The antenna' 

 arc punctured and coarsely pubescent, as long as the body; the 

 head is short aud perpendicular in front; the eyes narrow, emar- 

 ginate so deeply as to be completely divided, not linely granu- 

 lated ; the palpi are unequal, the labial short, the maxillary 

 elongate, last joint triangular, obliquely rounded at tip; the 

 front coxae are large, globose, and contiguous, scarcely angulated 

 externally, the lateral lissure being only narrowly open ; the 

 middle coxal cavities are angulated externally, but the sternal 

 pieces come in contact so as to cut off the episterna; the episterna 

 of the metathorax are wide in front, narrowed and pointed 

 behind; the legs are stout, the thighs strongly clavate, the spurs 

 small, and the 1st joint of hind tarsi longer than ihe two follow- 

 ing united. 



Dicentrus Bluthneri Lee, a much smaller Californian species, 

 also belongs to this group. It differs generically by the sides of 

 the prothorax having au additional acute spine near the base; 

 the thighs are not clavate. The color is pieeous, the elytra have? 

 each two large brown spots. 



The singular character which distinguishes this from all other 

 groups is, that the thickened hind niai'gin of the prothorax is 

 i)roadly emarginate in the arc of a circle, and the eniargination 

 filled with a thin corneous plate. The niesonotum is punctured 

 each side, with a very broad and flat, extremely fine, stridulating 

 surface. 



Group III. — Smodici. 



Smodicum ciicujiforme (Say), a .'^niall narrow depressed pale- 

 yellow species, found under bark in the Atlantic States, constitutes 

 by itself a distinct group, charatnerized by the mesothoracic 

 epimera being narrowed and acutely ])ointe(i inwards; the middle 

 coxal cavities are widely open externally. 



