164 MEMOIRS ON THE COLEOPTERA 



Colorado, and 3 mm. in length, judging at least by the blackish- 

 piceous legs, said to be black in acutifrons, but the prothorax in 

 scenicum is probably much more transverse. In cautum Lee., of 

 the Rocky Mountains, the prothorax is said to be no wider than the 

 head, the legs pale and the elytra deeply striato-punctate; it is 

 probably related remotely to tersum, from Lake Tahoe, the latter 

 differing very much in the feeble unimpressed striation and in its 

 darker legs. Umbraticum is remarkable in having no trace of the 

 very constant carina of the hind thoracic angles. 



Amerizus Chd. 



There can be but little question that this is a valid genus and not 

 a mere group of Bembidion; this is rather conclusively proved by 

 the subanchylosed external maxillary lobe. In the facies of the spe- 

 cies it truly approaches the trechiforme group of Bembidion, but 

 this resemblance, I am convinced, is largely superficial, as is its 

 still stronger similitude with some forms of Trechtis, but, as if to 

 accentuate the possible afcnity with Trechus, the last joint of the 

 labial palpi is often elongated to a degree probably unknown in 

 Bembidion; in most of the species it is in fact fully half as long as 

 the penultimate joint and sometimes longer. It is to be admitted, 

 however, that in the greater part of its organization it is very closely 

 allied to Bembidion, having the same male tarsal characters, and 

 relationships of the sclerites of the under surface, but it differs 

 greatly in the small and but slightly prominent eyes, with corres- 

 pondingly greater space separating the eyes from the broad, shallow 

 and parallel frontal sulci. The mentum tooth is well developed 

 and sharply triangular. The elytral fovese are on the third inter- 

 val. The species are moderately numerous, and those before me 

 may be defined as follows : 



Sides of the pronotum steeply sloping, the edge very finely reflexed. 

 Body subparallel, moderately convex, piceous-black, rather shining, 

 the head feebly micro-reticulate, the pronotum and elytra with very 

 fine and close-set wavy strigilation, visible only under rather strong 

 magnification; under surface of the hind body and the legs rufous; 

 head orbicular, somewhat longer than wide, three-fourths as wide 

 as the prothorax; antennae very thick, filiform, clear testaceous 

 throughout, three-fourths as long as the elytra, the medial joints 

 twice as long as wide, cylindric; prothorax between a third and fourth 

 wider than long, widest near anterior third; base slightly wider 



