Oct.,i9i6 Bulletin of the Brooklyn Entomological Society 75 



Cossonus pacificus n. sp. Black, shining. Head quite smooth except for 

 a few fine and sparsely placed punctures, rostrum moderately coarsely and 

 closely punctured at sides and rather finely and sparsely above. Eyes 

 moderate and but very slightly protruding beyond sides of head, diameter 

 of head across eyes slightly greater than dilated portion of rostrum. 

 Sides of head gradually convergent forwards, slightly constricted in front 

 of eyes to rostrum, a small fovea at middle of vertex. Rostrum as long 

 as one half of the thorax and but slightly arcuate, basal portion barely 

 longer than apical, narrowest a short distance in front of eyes, then grad- 

 ually increasing in width to apical portion which is one third broader than 

 narrowest portion, quadrangularly dilated and slightly broader than long. 

 Joints of funicle of antennae very slightly increasing in width outwards, 

 the outermost joint about one half the width of the club. 



Prothorax slightly longer than broad, base bisinuate, sides from slightly 

 constricted base, gradually arcuate to anterior third, then more suddenly 

 rounded to slightly constricted apex, surface flattened, unequally punc- 

 tured, the punctures along sides of median smooth line, coarse and sparsely 

 placed, very fine and sparse on outer part of disc and moderately coarse 

 and more closely placed at sides. At the base the longitudinal line be- 

 comes somewhat cristate. 



Elytra distinctly wider than thorax, with disc somewhat flattened, 

 striate, strise rather coarsely, evenly, and serrately punctured, intervals 

 convex, particularly posteriorly, very minutely uniseriately punctured. 



Body beneath moderately coarsely and closely punctured anteriorly and 

 more finely and sparsely punctured posteriorly. 



Length 7 mm., width 1.75 mm. 



Type: In my own collection; paratypes in U. S. Nat. Mus. and Cal. 

 Acad, of Sciences, all from Tallac, Lake Tahoe, Cal., June, 1899, and 

 taken by myself from beneath bark of dead aspen, Populus tremuloides 

 Michx. 



This species is the one which I considered, in my previous 

 paper, as the western phase of C. suhareatus Boh. and which I 

 now, after a more thorough and renewed examination, feel must 

 be considered as distinct. All my previous notes referring to 

 western localities for C. suhareatus Boh. must therefore be con- 

 sidered as appHcable to this species. A giant form from Field- 

 brook, California, collected by H. S. Barber, and now in the 

 Nat. Mus. Coll., I must at present consider as nothing but a very 

 large female of this species. This species differs from the true 

 C. suhareatus Boh. in being generally broader and flatter, the 

 other being quite cylindrical; in having the elytra much more 

 coarsely punctured and with more convex intervals ; the under- 



