NORTH AMERICAN COLEOPTERA. 267 



The head is less transverse than usual from the fact that the sides of 

 the clypeus are more nearly parallel. 



Occurs from Canada southward to Florida and'from Massachusetts 

 to Illinois. It seems rare in every localitv. 



CRENIPHILUS Motsch. 

 Maxillary palpi short and stout, the terminal joint longer than 

 the preceding. Prothorax without basal marginal line. Elytra 

 never either striate, or with regular series of punctures, sutural striL 

 deep, but obliterated at basal fourth. Posterior femora glabrous 

 except in injmcatm. Posterior tibia? fimbriate at apex with rela- 

 tively coarse and long spinules, unequal in length and not closely 

 placed. Posterior tarsi variable, sometimes slender and longer than 

 the tibia?, often stouter and rather shorter than tibife. 



In addition to the above diagnosis it may be more specifically 

 stated that the elytra are punctured in a confused manner, althou4 

 in several of the species a faint tendency to a linear arrangement 

 may be observed, especially near the apex. The head and thorax 

 are entirely deprived of the series of larger coarse punctures so well 

 marked m all the species of the preceding genera, except in three 

 Hydrobius. From the manner of elytral sculpture it must be evi- 

 dent that the coarse punctures arranged in series must also be absent 

 The mesosternum may be either absolutely plain or more or less 

 protuberant, but never greatly. The prosternum is cariuate in 

 several species. 



In separating our small species of Hydrobius from the laro-er ones 

 the desirability of which has been admitted by every systematist who 

 has studied them, the question of a name for the series presented 

 itself for serious consideration. 



^ In glancing over our species it will be seen that two forms occur 

 hrst those with the posterior femora opaque and pubescent, similar 

 to the other femora, represented in our fauna by injuscatus alone 

 secondly those with glabrous femora to the posterior legs, to which 

 the remainder of our species may be referred. The first series is 

 Anaccena Thorns, while the second contains some that are Pavacymm 

 Thoms., and others that would be excluded. Therefore neither of 

 the above names can be properly applied to the aggregate series 

 Castelnau's name Brachypalpus would be a very good one but his 

 genus is composed of Philydrus and Hydrobii. ' Mulsant'sVr/tom,. 

 IS founded on a species very plainly inseparable from Hydrobiul 



