AMERICAN nOLEOPTERA. 131 



P. calirornicns Motsch., h-ochantericus Lee. 



In this species the S hind tibiae are distinctly arcuate at basal third. 

 Northern California. 



The two unknown to us {/ulvus, angusticollis) should also doubtless 

 be referred to the same species with the other Arctic forms of Manner- 

 heim and Eschseholtz. 



The last three species in the above table have a tolerably close 

 superficial resemblance. The thorax is rather narrower behind in 

 rugicoUis and nearly square in californkits. While noticing the re- 

 markable differences existing between the males it is well to recall a 

 similar difference existing between two species of Ptercstichus, rostra- 

 tiia Newm., and grandiceps Chaud., ( nee Leconte ). As .«een from 

 above no differences whatever exist, while the latter has the hind 

 trochanter long and slender almost precisely as in Patruhus calif ornicin'. 

 Similar differences between otherwise closely allied species may exist 

 in other places in the Carabideous series and these two instances are 

 specially noticed here together that attention may be directed to further 

 observation. 



TRECHrS Clairv. 



Three forms occur in this genus, the first with oblong elytra which 

 are nearly twice as wide as long and with five or six striae moderately 

 well impressed; the second with oblong oval elytra with distinct 

 humeri and four or at most five striae, the inner three moderately well 

 and the outer two very feebly impressed ; the third has broadly oval 

 elytra the stride nearly obsolete sometimes with the two nearest the 

 suture feebly distinct. 



The following are the species . 



T. rubens Fab., elytra oblong. — Occurs in Northern Europe and Nova 

 Scotia. 



T. chalybseus Mann., elytra oblong oval.— Occurs in Alaska. 



T. californicus Motsch., does not differ from the preceding. — Alaska, Cali- 

 fornia, Oregon. 



T. micans Lee, I can see no difference excepting a somewhat paler color; 

 f ulcus Lee, is immature. — New Hampshire and Lake Superior. 



T. ovipeunis Motsch., elytra broadly oval.— Alaska. 



T. loevigatus Lce, does not differ from ovipennis. — California and Oregon. 



BE^nBIDIUM, Latr. 

 B. Wingatei Bland, Proc, Am. Ent. Soc. 1864, p. 319 is ohlongnlum 

 Mann. This species originally described from Alaska occurs in Canada, 

 Michigan and Pennsylvania. It has been referred to Trechus by Chau- 

 doir, but the external maxillary lobe is formed exactly as in Amerizus 

 and the species should therefore be placed in that genus. Amerizus 

 spectahilis Mann., is well known to American students. 



