138 GEO. H. HORN, M. D. 



Among the genera of the first group Lacordaire places Amhlytelus 

 Erichs. After a careful examination of the species on which it is 

 founded I believe that author to be entirely correct. It is however an 

 exception in the entire tribe, as far as I know, in having the fourth tarsal 

 joint bilobed on all the feet. The general appearance of the species is 

 rather that of a Callidide but the entire elytra with the well marked 

 internal plica indicate the correctness of its reference here. The group 

 Trigonotomae seems however rather unnatural and should in all probability 

 be separated. Amhlytelus will in any event represent a distinct group. 



The group Pterostichi is the only one represented in our fauna and 

 the number of the genera must remain the subject of discussion until 

 a thorough monograph shall have fixed their limits. Those of our own 

 fauna require discussion here. 



In order that the reader may have some point of departure from 

 which to follow the argument I reproduce the table of genera given 

 by Dr. LeConte in his last discussion of the subject, (Proc. Acad. 1873, 

 p. 302), to which I add Myas and Amara. 



Last joint of palpi dilated. Mentum tooth obtuse Myas. 



Last joint of palpi cylindrical or slightly oval. 



Mandibles striate; elytra with one dorsal puncture Evarthrus. 



Mandibles not striate. 

 Mentum tooth emarginate. 

 Ligula carinate. 



Metathoracic episterna long Lophoglossus. 



Metathoracic episterna short Holciophorus. 



Ligula not carinate. 



Front tarsi of %, normally dilated. 



Second joint of labial palpi bisetose Pterostichus. 



Second joint plurisetose Amara. 



Front tarsi of %, obliquely dilated Loxandrus. 



Mentum tooth entire Piesmus. 



In Myas the characters are undoubtedly valid and in addition it might 

 be added that the ligula is quadrisetose in front, a character figured by 

 Migneaux but not mentioned by Duval. The elytra have no dorsal 

 puncture and the mandibles are obliquely striate. 



The striation of the mandibles which seems to have been a character of 

 last resort in the separation of Evarthrus will not by any means hold 

 good with many species of Pterostichus, {rostratus, tumescens, mancus, 

 coracinus, etc.), which have the mandibles more deeply striate than very 

 many Evarthrus. 



The species of Evarthrus are readily separable into two series, the 

 first has the penultimate joint of the labial palpi longer than the last 

 and with three or four long setae, the second has the terminal joint 



