8 MEMOIRS ON THE COLEOPTERA. 



shining, pale piceo-flavate, the head and abdomen slightly darker, 

 blackish-piceous, the legs pale; punctures moderately large, rather 

 close-set, finer and less conspicuous on the abdomen, the vestiture pale, 

 short, rather abundant; head parallel, with rounded sides, as long as 

 wide, the antennae fully half as long as the body, brown, gradually 

 pale basally, gradually incrassate and heavy distally, the second joint 

 equal in length to the first but more slender, shorter than the third, 

 the fourth much longer than wide, ninth as long as wide, tenth a little 

 wider than long, the last gradually obtusely pointed and as long as 

 the two preceding; prothorax one-half wider than the head and nearly 

 one-half wider than long, parallel, the sides evenly arcuate; base wider 

 than the apex, broadly rounded, the angles obtuse and rounded; surface 

 evenly convex and punctate, with a rounded impression before the 

 scutellum; elytra large, but little shorter than wide, slightly wider and 

 much longer than the prothorax, the sides feebly diverging from the 

 base, the apices broadly sinuate laterally; abdomen distinctly narrower 

 than the elytra, the sides feebly converging and slightly arcuate from base 

 to apex, the fifth tergite much longer than the fourth; sixth ventral, 

 in the type, very narrow and narrowly rounded. Length 3.0 mm.; 

 width 0.9 mm. California (Licking Fork of the Mokelumne River, 

 3000 ft.), Blaisdell-Letcher. 



To be known easily by the long heavy antennae, pale coloration, 

 large elytra and distinct punctuation, the latter being stronger 

 though sparser on the pronotum than in disjuncta Csy. 



Rheobioma marcida n. sp. Much more slender and parallel, moder- 

 ately convex, strongly shining, testaceous, the head a little darker, 

 the elytra somewhat yellowish, the abdomen feebly clouded except at 

 apex and toward base, the legs pale; punctures rather fine and close, 

 evidently dense on the elytra, still finer but numerous on the abdomen, 

 the vestiture palish, fine, short and abundant; head as long as wide, 

 parallel and broadly rounded at the sides, the antennae piceous-brown, 

 slightly paler basally, rather short, gradually and distinctly incrassate 

 distally, the second joint a little longer than the first and very much 

 longer than the third, the outer joints distinctly wider than long, the 

 last short, obtuse, not as long as the two preceding; prothorax relatively 

 smaller than in the preceding though of the same general form, rather 

 shorter and less convex, scarcely two-fifths wider than the head, the 

 ante-scutellar impression distinct, transversely oval ; elytra well developed, 

 slightly shorter than wide, distinctly wider and very much longer than 

 the prothorax, the sides very feebly diverging from the base, the 

 apices rather deeply sinuate laterally; abdomen narrower than the 

 elytra, parallel, narrowing a little only at apex, the fifth tergite much 

 longer than the fourth; middle coxae almost contiguous, the mesosternal 

 process more slender than in disjuncta though otherwise similar, the 

 metasternum transverse and feebly arcuate, much less so than in terrena. 

 Length 2.75 mm.; width 0.66 mm. California (Lake Tahoe). 



Readily distinguishable by its narrower and more parallel form 

 and much shorter antennas. 



