ioo MEMOIRS ON THE COLEOPTERA 



Pacific, excepting the Atlantic adoxus group, into several groups 

 based almost wholly upon general facies. These habital groups seem 

 to be entirely natural and clearly delimited subdivisions, as shown 

 when we come to examine their anatomy more in detail. Designating 

 these minor subdivisions by the names of certain well known species, 

 they can be recognized as once as follows: 



Group I planctus Lee. 



The species of this group are as a rule peculiarly parallel in out- 

 line, with subrectilinear sides, the polished pronotum depressed to a 

 greater or less degree, generally nearly flat and subquadrate, never 

 strongly narrowed behind and having the latero-basal impression 

 large, elongate and unusually conspicuous; the lateral edges are 

 frequently crenulate in a feebly marked and irregular manner and 

 the elytral striae almost always deeply impressed, with strongly 

 convex intervals. This simply gives a general sketch of the group, 

 the species of which are very numerous and possibly identifiable 

 as follows : 



Body more parallel, the elytra never more than just visibly wider than 

 the prothorax; hind tarsi shorter and usually much stouter, or at 

 least with the first joint always much shorter than the next two 

 combined, simple to very lightly grooved on the outer side; hind 



tibiae (cf ) more or less crenulate internally throughout 2 



Body less parallel, the elytra always rather distinctly wider than the 

 prothorax, the hind tarsi longer and more slender, with the first 

 joint always strongly grooved on the outer side and usually nearly 



as long as the next two combined 9 



2 Larger species, not under 16 mm. in length 3 



Smaller species, not exceeding 12 mm. in length 5 



3 Body deep black, slightly convex, rather dull in lustre; head two- 

 thirds as wide as the prothorax, the epistoma and labrum feebly and 

 evenly sinuate from side to side; antennae stout, attaining the thoracic 

 base, blackish, the basal joint dark rufous; prothorax slightly wider 

 than long, the sides broadly rounded, feebly converging and broadly, 

 feebly sinuate basally, the base sinuate medially, four-fifths the 

 maximum width, the impressions at each side broad and feeble, 

 subconfluent; elytra oblong-oval, one-half longer than wide, obtusely 

 but not abruptly rounded at apex, nearly a fifth wider than the 

 prothorax, the striae very fine, scarcely at all punctulate or impressed, 

 the intervals almost flat, convex laterally; hind tarsi short and not 

 very stout, the joints normal in form, narrowing basally and feebly 

 inflated apically; serrulation along the inner edge of the hind tibiae 

 unusually distinct though obtuse; female much smaller than the 

 male. Length (cf 9 ) 17.5-20.0 mm.; width 6.2-7.0 mm. Cali- 

 fornia serripes Lee. 



