OF TIIK UNITED STATICS. 397 



anterior tarsi of the male have two dilated joints, of which the first is the larger: in P< ri- 

 compsus, this dilatation is wanting, the tarsi being alike in both sexes. The genua Pogonus 

 bcloiiufs in this group; the only American species described, I', minutus Dej. bas never 

 come under my notice. 



I am doubtful respecting the position of Patrobus, which seems to have very Btrong re- 

 lations with Ptcrostichus, and ought probably to form a Beparate group in the preceding 

 subfamily: the epistcrna are not as diagonally divided as in the other g< m ra placed here, 

 but their posterior part is slightly triangular in form. 



Our genera may be thus arranged : 



A. Palpi subulati. 



Oculi nulli ----- . Anillufl D 



Ocidi distinct i, tibia: anticai oblique truncate : 



Antenna: articulo 3 10 contiguis minorc - - .up. 



Antenna articulo 3 io contiguis sequab" - - onipsus /. . 

 Oculi distincti, tibia: anticse apicc recto truncatae. 



Mentum dente medio plus minusve distincto, integro - Ochthedromus /. 



Mcntum dente medio brevi, emargii - - Bydriuni /. 



Mentum trilobum, lobo medio non breviore - - limn / 



B. Palpi cylindrici - - .... Patrobus /' 



Anillus was established by Jacquelin-Duval, (Ann. Ent. Sue. l'r. 1851, Ixxiii.) upon a 

 very small species found in the southern part of Prance: among my California ins< cts I 

 find three specimens of a nearly allied species, found under .-lone- at San Jose: no si xual 

 difference can be perceived. It may be thus defined : 



A. d e b i 1 i s , apterus testaceus, viz parce pubescei ice latitndine non brei 



posticc valdc impresso, angulis posticis minutis n olete striato-punctulal 



subtilissimc alutaccis. Long. '05. 



Pericompsus is described ly me in the Annals of the Lyceum, Vol. 5: it contains 

 Tachys ephippiatus Say, and two allied new species. 



W ith Ochthedromus must be united Odontium /."■. (Ann. Lye. I, 152, the < haracters 

 not being Bufficienl for a well defini . The species of Ochthedromus, in which the 



front is sculptured with converging furrows, (O. angulifer, connivi ns, cautus, and frontalis 

 Lee.) have the labrum smaller than in the othi , and emai , bul there d 



not appear to be sufficient different ble them to be separated. 



Bembidium will contain, then, onlj th ecies having impn ed ian on the 



elytra: in addition to the peculiar form of the mentum, the 6rst joinl of the anterior t 

 of the male is much larger than in the othi r genera. 



Of Patrobus, there are known to me three nativi : P. longicorni s 



[Americanus Dej. ;) P. angicollis Randall, ( Bost, Jour. Nat. Hist. 2, 1, i od P. t< du 

 Lee. (Pterostichus tenuis \jbc. \ iss. Lac. Sup. 207;) the type of the latter it a female, and 

 except in the ant< nnse and episterna of the mesothorax, precise!} resembli - a Pt< rosti< bus. 



Pogonus rectus Say, as already Bhown l>y me, Journ. Vcad. Nat. v ' . 2d 

 is a species of Loxandrus, a genus of Pterosticbi. 



