268 MEMOIRS ON THE COLEOPTERA 



width 0.8-0.9 mm. Rhode Island to Lake Champlain and Iowa. 

 Very abundant. [Stenolophus carus Lee.; ITrechus immunis Kirby]. 



cams Lee. 



Form much stouter but otherwise somewhat similar, very shining, piceous- 

 black, the prothorax throughout testaceous; legs pale; head some- 

 what larger, three-fourths as wide as the prothorax, the eyes smaller 

 but prominent and somewhat longer than the neck; antennae obscure 

 testaceous, only moderately slender, not quite as long as the elytra, 

 the joints short as usual; prothorax as in carus, except that the 

 converging sides are not so straight posteriorly and the obtuse basal 

 angles evidently rounded; surface nearly similar but with the 

 impressed part near the angles almost completely punctureless; 

 elytra barely a third longer than wide, feebly inflated posteriorly, 

 still more broadly obtuse at apex, the sides broadly arcuate, only a 

 third wider than the prothorax; striae fine, the scutellar very short 

 and feeble; intervals nearly flat, the discal puncture near three-fifths; 

 tarsi nearly similar. Length (9 ) 2.6 mm.; width i.o mm. Rhode 

 Island (Boston Neck). Two examples nanellus n. sp. 



Form stouter than in carus, the size less minute; surface very moderately 

 convex, very shining, deep black, the prothorax fusco-testaceous; 

 legs pale; head still larger, though not so large as in hydropicus or 

 expertus, nearly four-fifths as wide as the prothorax, the eyes moder- 

 ately large and prominent; antennae much more slender and with 

 longer joints than in the two preceding, blackish, the first much, 

 the second slightly, paler, half as long as the body; prothorax nearly 

 as in the preceding, two-fifths wider than long, the sides rounded 

 anteriorly, oblique and nearly straight basally, the basal angles 

 obtuse and very narrowly rounded; depression near the hind angles 

 with a few sparse punctures; elytra oblong, parallel, differing from 

 any of the preceding in not being sensibly inflated posteriorly, the 

 sides broadly arcuate, the apex broadly obtuse, with a short but 

 distinct sinus; striae fine, evidently though irregularly impressed as 

 a rule, the scutellar not long but distinct; intervals feebly convex; 

 tarsi fuscous, slender, of the usual structure. Length (c? 9 ) 2.4-2.8 

 mm.; width 0.85-1.0 mm. New York (Lake Champlain). 



trivialis n. sp. 



It is possible, as suggested by LeConte, that cams may be the 

 same as the Trechus immunis of Kirby, but there are evidences of 

 other species besides those here described, more especially one, 

 represented by two examples labeled "Ontario," which are a little 

 larger in size and of more elongate form than the typical carus and 

 this may be the true immunis. The species in the carus group are 

 rather closely allied among themselves. In hydropicus the head is 

 relatively not quite so wide as in expertus, but is very peculiar in 

 its long neck and comparatively small and feebly convex eyes. 



