1QK 



1873.] x — ° [Horn. 



Body above piceous black. 



Sutural stria obliterated at basal third nigrella. 



Sutural stria very fine at basal third, but visible. . . atra. 



Elytra testaceous, head black pallida. 



These species are all very convex, shining, scarcely punctulate, the 

 first two piceous black, the sides of the thorax piceo-testaceous and par- 

 tially diaphanous, the sides of elytra are similarly margined, the extent 

 of the pale portion becoming greater toward the apex. The third species 

 is entirely pale piceo-testaceous, the head alone being black and shining. 



0. nigrella, Lee. (Cyllidium) Proc. Acad. 1861, p. 342. 



The sutural stria of the elytra is rather deeper than in the following 

 species, but without any trace at the tarsal third. Length .06 inch ; 

 1.5 mm. 



Occurs in California, at San Diego and Yisalia. 



C- atra, Lee. {Cyllidium) Xew Species, 1863, p. 24. 

 Length .08 inch ; 2 mm. 

 Occurs in Xew York. 



C. pallida, Lee. (Cyllidium) Proc. Acad. 1861, p. 342; nigriceps, Lee. 

 loc. cit. 



Length .04-. 06 inch ; 1-1-5 mm. 



Occurs in California and also at Lake Superior. I find it impossible to 

 separate the types of the two above noted. 



Laccobius. Er. 

 Two species are described in our fauna. 



L. agilis, Rand. Bost. Jouro. 2, p. 19 ; punctulatits, Mels. Proc. Acad. 

 2, p. 100 ; Lee. Proc. Ac. 1855, p. 363. 

 Length .08-. 12 inch ; 2-3 mm. 

 Extends from the Middle States westward to California and Oregon. 



L. ellipticns, Lee. Proc. Acad. 1855, p. 363. 



Length .10 inch ; 2.5 mm. 



These two species resemble each other very closely. The latter is less 

 broad and the punctures of the disc of the elytra less distinctly arranged 

 in rows, being in the large majority of specimens very confused. 



Occurs in the southern regions of California and in Arizona and Lower 

 California. 



The two genera which follow, Philhydrus and Hydrobius, differ in the 

 relative length of the joints of the maxillary palpi, the terminal joint 

 being shorter than the preceding in the former and longer in the latter. 

 By an error on the part of the compositor the two genera are transposed 

 on page 47 of the Classification of the Coleoptera of North America, 

 characters the reverse of those above indicated are thus presented to the 

 student. The genus Sperchopsis there indicated will be found included in 

 Hydrobius as the palpi are absolutely identical. 



