Monograph of the Species op Pasimachus inhabiting the United 

 States ; with Descriptions of two New Genera, belonging to 

 the family Carabica. By John L. Le Conte. Read Novem- 

 ber 9th, 1845. 



The genus Pasimachus was established by Bonelli, on two 

 large North American Carabica, descrihed by Fabricius as Scarites; 

 a species discovered by Palisot de Beauvois was found to be con- 

 generic with them, and shortly afterwards our distinguished com- 

 patriot, Mr. Say, described a fourth species. A fifth was detected 

 in Mexico, and very recently Mr. Haldeman has added to the 

 Fauna of the United States another, which he communicated to 

 the scientific world, through the Academy of Natural Sciences of 

 Philadelphia. 



Having collected a great number of specimens from different 

 parts of our country, on submitting them to examination, several 

 new species were rendered apparent, and in view of this fact, it 

 was thought necessary to prepare a short notice of them. To facil- 

 itate the determination of these, it was deemed expedient to 

 introduce descriptions of the species heretofore mentioned by au- 

 thors, more especially as several important characters appear to 

 have been overlooked. The paper has thus assumed somewhat 

 the form of a monograph, though I should scarcely wish to dignify 

 a work so imperfect by such a name. 



To avoid repetition, I follow the example of Westwood in class- 

 ing with the generic marks, all those characters which appear to 

 be constant in every species, although of such slight importance as 

 scarcely to be regarded essential to the constitution of the genuB. 



Pasimachus is nearly allied to Scarites, Acanthoscelis, Oxygna- 

 thus, Carenum, and several other genera of the Scaritides, by means 

 of its obtuse maxillae ; in the firstof these genera the tooth with which 

 this organ is usually terminated, exists in a very rudimentary state, 

 and in the others it is not perceptible. In its dentated mandibles 

 it resembles Carenum, Scarites, and a few others. By the woll- 

 marked posterior angles of the thorax, it exhibits a leading off to- 



