56 MEMOIRS ON THE COLEOPTERA 



process and the flattened porrect tip of the prosternal process, which 

 bears a loose fringe of stiff setae along its apical edge. The mentum 

 is narrower than in Olibrus, the front rather more constricted between 

 the large antennal recesses and the last joint of the maxillary palpi 

 is somewhat more securiform; the scutellum is small or moderate 

 as in Olibrus, but, unlike that genus, the elytra never have more than 

 a single stria placed near the suture, generally coarse and deep and 

 sometimes, as in piisilla, coarsely punctured in part; occasionally, 

 however, as in subalutaceus , it becomes very fine and in certain 

 species wholly obsolete, except a feeble trace on the apical slope. 

 The elytral punctures are small, sometimes, as in apicalis, virtually 

 wanting; in other cases, such as pusillus and attenuatus, distinct in 

 the inner series, except toward base and apex, but they never assume 

 the very broadly crescentic and scratch-like form characterizing 

 Acylomus and there are, furthermore, no perceptible sexual modifi- 

 cations of the hind tibiae, which are so conspicuous in that genus. 



I have before alluded to a small tubercle half buried near the 

 base of the first antennal joint. This is a singular formation and is 

 really a knob-like attachment on the posterior part of the base of 

 the joint, resting and moving within an extension of the antennal 

 socket. It is present in apparently all the genera of the family 

 but is especially developed in Stilbus* and probably serves as a 

 point of attachment for muscles giving special movements to the 

 antennae. 



The numerous species at hand may be arranged as follows: 



The subsutural stria of the elytra deep and distinct, though, as usual in 

 the family, abbreviated basally 2 



The stria obsolete except posteriorly, where it is fine and very feeble; 

 body small in size and notably narrow 29 



2 Elytra without micro-reticulate ground sculpture, except occasionally 

 and more or less feebly toward apex, this rather evident in pallidns . 3 



* It would give me special pleasure to use the name Eustilbus suggested by Dr. 

 Sharp for this genus, as a substitute for Stilbus, on the ground of grammatical inter- 

 ference with the older Stilbum, were it not for certain reasons, which, however, being 

 personal so far as ascertainable, may after all be of but little value. One such reason 

 is the feeling that generic names should be regarded as constants, wholly independent 

 of linguistic rules and the vagaries of grammatical construction, in other words, that 

 they should be held to be indeclinable, except when used in the genitive as specific names. 

 Under this conception it is unnecessary to change the name, and it seems also almost 

 certain that such action would form a precedent endangering the stability of nomen- 

 clature to some extent. 



