NORTH AMERICAN COLEOPTERA. 257 



the apex, the outer five scarcely impressed, striae entire, composed of moderately 

 impressed, closely placed punctures, the inner strife scarcely reaching the middle 

 from apex, the sutural stria well impressed and longer, the coarser punctures of 

 the intervals 3-5-7-9 barely distinguishable. Body beneath piceous, opaque. 

 Femora piceous, opaque, tibije and tarsi rufo-testaceous. Length .20— .24 inch.; 

 5 — 6 mm. 



Prosternura entirely simple, mesosternum with a short, arcuate, transverse 

 ridge, slightly in front of the coxae. 



Tarsal claws similar in the sexes, slender, feebly arcuate, slightly broadened 

 toward base. 



This species is similar in sculpture to dorsalis, but the strife and 

 punctures are much less impressed and the coarser punctures of the 

 alternate intervals very feebly indicated. The raesosternal ridge in 

 that species is a straight transverse line, here it is very strongly ar- 

 cuate. The color of the two species is also quite distinct, that being 

 always piceous, while this is an indefinite rusty-brown or pale chest- 

 nut color, resembling at first sight Phil. Hamiltoni. 



Occurs in California from Tejon northward. 



C. rotnnda Say. — Very broadly oval, moderately convex, piceous, shining, 

 border indefinitely paler. Thorax closely punctate, more sparsely toward the 

 sides, the arcuate and transverse series of coarse punctures well marked. Elytra 

 punctured similarly to the thorax, but less closely near the apex, the two innei- 

 series of coarse punctures very indistinct, the outer series well marked, sutural 

 stria deeply impressed, extending two-thirds to base. Body beneath black, sub- 

 opaque. Femora and tibiae piceous, the tarsi pale. Length .26 — .28 inch. ; 6.5 — 

 7 mm. 



Prosternum simple, mesosternum with a transverse ridge elevated in an an- 

 gular form so that when viewed posteriorly it presents the form of a broad A- 



Tarsal claws simple and slender in the two sexes. 



This species is the most 'broadly oval of any in the Philydride 

 series. In the specimen before me the elytra seem slightly explanate 

 at apex, but this may be an individual character. 



In previous papers Dr. LeConte has compared the species with 

 Hydrobius globosus, while I have suggested Philydrus cinctus. Neither 

 comparison is very satisfactory, inasmuch as it is far less convex 

 than the former and more broadly oval than the latter. It is not 

 very greatly different in form and appearance from some of the 

 larger specimens of H. fimbrlatus, although more decidedly oval. 



It seems to be quite rare in collections, being represented, as far as 

 known to me by one specimen each from the Middle States region 

 and North Carolina in the cabinet of Dr. LeConte and one in my 

 own collected near Tewksbury, Mass., and kindly given me by Mr. 

 Blanchard. 



TKANS. AM. ENT. SOC. XVII. (33) AUGUST, 1890. 



