404 MEMOIRS ON THE COLEOPTERA 



tarsi shorter and thicker than in the preceding forms. Length 

 (cf) 5-7 mm.; width 1.2 mm. Montana (Mullan), Wickham. 



densiventris n. sp. 



Dr. Horn, in describing debilis (1. c., p. 165), confused two distinct 

 species, as shown by size, outline of the body, relative size and 

 strength of elytral punctuation and sexual characters at the apex of 

 the last ventral plate ; as he mentions Clear Lake first in his citation 

 of localities, I assume that the larger and more strongly punctured 

 form is the typical debilis and have so identified it above. Of 

 nanulus, which is a more northern species, shorter, more parallel 

 and more compact than debilis, with very much smaller and feebler 

 notch at the ventral apex of the male, I have a large series from 

 Siskiyou Co., exhibiting no notable variability; possibly it may be 

 the same species as the Vancouver specimen cited by Horn under 

 his description of debilis. 



Distichalius n. gen. 



The chief characters distinguishing this group from Microsaurus, 

 are the instability of elytral sculpture and the presence of two 

 punctures, or less definite impressions, arranged transversely on 

 the discal part of the front and not to be confounded with the usual 

 very persistent puncture in nearly the same line but adjoining the 

 eye. I am by no means satisfied that these characters will serve 

 effectively for more than subgeneric distinction, although in com- 

 paring Quedius capucinus and fulgidus, the differences in habitus 

 seem to be very pronounced and apparently generic. The two 

 punctures of the front referred to, are apt to appear accidentally in 

 more or less irregular form in some other, not closely related species, 

 and, in puncticeps Horn, they are also present but are larger and 

 more widely separated than in any species of Distichalius. The 

 species are rather numerous, those now in my collection being 

 definable as follows: 



Elytral punctures wholly wanting on a large part of the surface 2 



Elytral punctures covering the entire surface but sparse and very ir- 

 regular, in great part fine, but with coarser punctures intermingled 

 toward the sides 3 



Elytral punctures closer, stronger and evenly distributed throughout 

 the surface 4 



2 Body moderately stout and convex, shining, deep black throughout, 

 the legs piceous, the antennae blackish; head somewhat quadrate- 



