244 MEMOIRS ON THE COLEOPTERA 



minutely prominent or rounded; the sides are, however, never 

 broadly sinuate basally, with sharply marked right angles, as they 

 are in the next five genera of the table given above. The elytra 

 always have a discal puncture well behind the middle and a clearly 

 defined annular basal fovea, but there is seldom any trace of a 

 scutellar stria or apical sinus, the elytra always being evenly and 

 circularly rounded at tip; the lateral line of foveae are widely inter- 

 rupted medially. The emargination of the mentum is rather 

 shallow, the tooth narrowly acute and well developed. The labial 

 palpi are of quite a different form from that characterizing the 

 preceding genus; the second joint is unusually short, broad, flat- 

 tened, subtriangular, with the anterior edge acute and bearing two 

 long seta?, the third joint distinctly longer, inflated basally, finely 

 subulate apically and with a deep impression at least in the male. 

 The inner lobe of the maxilla is strongly hooked at apex and the 

 last joint of the outer lobe gradually inflated basally and drawn 

 distally into a long slender subulate apex. The antennse are 

 slender and the third joint does not have any of the very short 

 decumbent pubescence borne by the following joints, though 

 having numerous erect setae. The frontal fovese are deep and are 

 prolonged in a fine oblique line to the eyes. Male sexual characters 

 will be described under severaj specific headings below. The 

 species are very numerous but rather closely allied among them- 

 selves in some parts of the series and especially near rupestris; they 

 are widely distributed over the entire continent as far southward as 

 the table land of Mexico and are generally abundant individually. 

 Those represented in my cabinet are as follows: 



Hind angles of the prothorax obtuse but not rounded and more or less 



evidently though minutely prominent 2 



Hind angles distinctly and broadly rounded 26 



2 Body less minute, between 3 and 4.5 mm. in length 3 



Body minute, always distinctly under 3 mm. in length 21 



3 Species of the Atlantic region; surface always very shining 4 



Species of the Rocky Mountain and Sonoran regions 10 



Species of the true Pacific faunal region 14 



4 Antennae notably stout. Body and legs testaceous in color, the head 

 but little darker, the elytra with a large blackish cloud posteriorly; 

 under surface of the hind body black; head three-fourths as wide as 

 the prothorax, with the usual prominent eyes; antennae half as long 

 as the body, fuscous, paler basally; prothorax a fourth wider than 

 long, widest near apical third, the sides there rather strongly rounded, 



