AMERICAN COLEOPTERA. 121 



Group SCARITES. 



In our fauna two genera occur separated in the following manner : 



Hind angles of thorax distinct. Elytra with humeral carina of variable length. 



Maxillse very obtuse at tip Pasimachus. 



Hind angles of thorax wanting. Elytra without humeral carina. Maxilla? slightly 



hooked at tip Scarites. 



In these two genera the four basal joints are glabrous and in repose 

 the scape is received in a depression beneath the eye. 



Group CLiviNiE. 



The genera which occur with us are as follows : 



Margin of elytra entire. Mandibles flat and arcuate. 

 Anterior tarsi slender in both sexes. 



Palpi dissimilar in the sexes, the terminal joint more dilated in the male, 

 excavate beneath with a large sensitive space. Thorax globose or globose- 

 oval Dyschirius. 



Palpi similar in the sexes, not dilated nor excavated in the male. Thorax 



more or less quadrate CI i Vina. 



Anterior tarsi more or less dilated in both sexes. 



Mentum feebly emarginate. Head not grooved Aspifloglossa. 



Mentum deeply emarginate. Head with numerous longitudinal grooves. 



Scliizogenius. 



Margin of elytra interrupted posteriorly and with an internal j)lica. Mandibles 



slender, prolonged not arcuate. Anterior tarsi of both sexes rather 



widely dilated Ardistoniis. 



In the arrangement of the genera of this group I regret that I am 

 unable to follow my friend M. Jules Putzeys, nor can I from my 

 dissections find the ligular characters which he aims to illustrate in 

 his Postscriptum (Mem. Liege xviii, 1863). The dissection of the 

 species of this group is by no means an easy task, and the difficulties 

 attendant on its accomplishment must be the cause of the entire 

 absence of resemblance between the drawings of M. Putzeys and the 

 objects themselves. 



In all our genera the ligula is small and is usually hidden by 

 the supports of the labial palpi. The ligula is slender, the tip more 

 or less acute, free and biseti'gcrous the paraglossse slender and acute, 

 not longer than it. The form of the maxillae, mentum, ligula and 

 palpi, are shown in the accompanying figures and need no further 

 description. Clivina and Dyscliirius are best separated by the form 

 of the palpi, all other characters heretofore given fail in our series 

 of species. 



As arranged in the preceding table our genera show the transition 

 from the simple form of inner maxillary lobe of PasimacJms to that 

 which is the more common form in all Carabidse. 



TRANS. AM. ENT. SOC. IX. (2C) AUGUST, 1881. 



