42 AMERICAN COLEOPTERA. 



about one-half as long as the body, black. Prothorax rather more than one-half 

 wider than long, as wide at base as apex, finely and sparsely punctulate at base ; 

 apex feebly emarginate ; median line either entire or abbreviated in front; trans- 

 verse impressions moderately distinct, the anterior sometimes rather feeble ; basal 

 impressions broad, deep, bistriate ; sides with the margin very narrowly reflexed, 

 arcuate in front, scarcely sinuate behind ; hind angles subrectangular. strongly 

 carinate. Elytra about one-half wider than the thorax, with the two or three 

 inner strife very fine, the others almost or entirely effaced ; strife very finely or 

 obsoletely punctulate, the first only entire ; intervals flat, the third with the first 

 dorsal puncture about one-third from base, the second about one-third from apex. 

 Beneath black, shining. Legs black, the tibise and tarsi sometimes piceous. 

 Length .14-.20 inch. ; 3.5-5 mm. 



Distinct from the preceding by the thorax not wider at base than 

 apex, with the basal impressions deeper and the hind angles more 

 strongly carinate. The elytra are proportionally wider as compared 

 with the thorax, much more finely striate, with all but the two or 

 three inner strise effaced. 



It occurs along the Pacific coast from Vancouver Island to Cali- 

 fornia, extending as far East as Nevada. 



Group iii. littorale. 



Maxillae with the outer lobe distinctly bi-articulate ; mentum 

 deeply emarginate, with a large, entire tooth ; frontal stri?e single; 

 deep, parallel ; eyes large and prominent. Prothorax subquadrate, 

 as wide or wider at base than apex, truncate at base, obliquely so 

 each side. Elytra with the third interval wider than the others and 

 with two impressed quadrate foveae, each enclosing a dorsal punc- 

 ture ; strise entire, the eighth distant from the margin; humeri sub- 

 angulate. The quadrate foveje on the third interval are peculiar to 

 this gi'oup, and give an easy means of distinguishing the species 

 belonging to it from those of allied groups. 



This is one of the best defined groups of the genus. The species 

 are rather above the average size, generally more or less bronzed 

 without testaceous markings, and usually with the surface of the 

 elytra uneven, alutaceo-granulate, wnth elevated smooth spaces, this 

 latter character being less marked in piuictatostr latum. It is the 

 equivalent of the first .section of Duval's second group (Ann. Soc. 

 Ent. France, 1851, ser. 2, ix, p. 452), that author including in his 

 second section those which I have placed in the next group. 



Five species are known to me. One, B. littorale Oliv., occurs also 

 in the old world. They may thus be separated : 



