168 Trans. Acad. Sci. of St. Louis. 



distinctly wider than the prothorax though less obviously so in hum- 

 boldti, the prothorax very faintly obtrapezoidal and distinctly voider 

 than long, with the sides nearly straight 7 



7 — Punctures sparse, the surface more shining; body notably stout, black- 



ish-piceous in color, the elytra paler and generally bright rufous, the 

 legs testaceous; head large, the antennae as long as the head and pro- 

 thorax, the elytra distinctly wider than the prothorax and as wide as 

 the head, rather longer than wide; gular sutures fine, straight and 

 parallel, approximate though sensibly separated and not impressed. 

 Sexual characters of the male identical with those of shastanicum, the 

 sinus of the fifth segment about two -thirds as wide as the segmental 

 apex but with the process virtually similar. Length 4.0 mm.; width 



0.95 mm. California (Sta. Cruz to Lake Co.) latiascnlnm Csy. 



Punctures close-set, the surface more alutaceous; body less stout 8 



8 — Body more evenly parallel, the prothorax notably larger and only 



slightly narrower than the head or elytra, blackish-piceous, the pro- 

 thorax, elytra, legs and antennae paler and piceo -testaceous; elytra 

 obviously longer than wide, a fourth wider and rather more than one- 

 half longer than the prothorax; gular sutures very approximate and 

 distinctly impressed. Sinus of the fifth ventral broad and well devel- 

 oped but not very deep, the process scarcely at all more than one -third 

 of its total width, broadly sinuate with rounded angles, its sides but 

 feebly divergent to the base ; fimbriate sides only very feebly, evenly 

 curved and but slightly narrower than the process ; surface of the seg- 

 ment feebly flattened toward the middle throughout, the flattened area 

 more finely and sparsely pubescent. Length 4.2 mm.; width 0.8 mm. 



California (Sta. Clara Co.) malacnm Csy. 



Body less evenly parallel, the elytra being notably wider than the head and 

 a fourth wider and one-half longer than the prothorax, not longer than 

 wide, still more finely and closely punctured, dark rufo-testaceous, 

 the head and abdomen blackish, the legs pale; abdomen notably nar- 

 rower than the elytra; gular sutures fine but distinct, not distinctly 

 impressed, very narrovyly separated. Sinus of the flfth segment nearly 

 as in malacum, but with the fimbriate sides evenly though more strongly 

 curved, only slightly narrower than the median process, which is more 

 broadly sinuate and nearly parallel-sided ; surface of the segment not 

 modified. Length 3.8 mm.; width 0.75 mm. California (Humboldt 

 Co.) hnmboldti n. sp. 



9 — Gular sutures almost completely contiguous and distinctly impressed ; 



head large, with the basal angles broadly rounded, notably wider than 



the prothorax 10 



Gular sutures very narrowly but perceptibly separated and not or very 

 feebly impressed; head only very slightly wider than the prothorax; 

 species smaller in size 11 



10 — Sinus of the fifth segment about three-fifths as wide as the apex, only 



moderately deep, the median process somewhat less than half as wide 

 as the sinus, with rounded lateral angles, sinuate throughout almost in 

 circular arc, the sinus five or six times as wide as deep ; sides of the 

 process slightly diverging to the base, the fimbriate sides of the 

 sinus rather strongly curved. Body finely, not very densely punctate, 



