AMERICAN COLEOPTERA. 127 



of any system of subdivision of the Carabidae. Knowing then that the 

 publication of the present paper in the form originally intended would 

 carry with it a very decided expression of the above opinion, I felt that 

 greater weight would attach to that opinion if some other system were 

 presented at the same time. This essay became a secondary matter and 

 the Classification of the Carabidae as presented in the preceding volume 

 was allowed precedence. 



The synoptic table of the genera will not be repeated here, nor will 

 I include Lebia, as nothing of importance has been added since my 

 paper published several years ago. 



The descriptions of the species are for the most part short, several 

 of the more troublesome genera only have received greater attention 

 in their details. 



TETRAGONODERUS Dej. 



This genus is a centre around which are grouped others having in 

 common a form of inner maxillary lobe which I have illustrated in 

 a series of dissections of Carabide mouth parts, (Trans. Am. Ent. Soc. 

 ix, pi. viii, fig. 80). The tibial spurs of the middle and posterior legs 

 are also long and slender and their margins very finely serrulate. 

 The terminal spur of the anterior tibia is more obviously serrulate 

 than the others. 



The tribe Tetragonoderidx as suggested by Chaudoir, (Bull. Mosc. 

 1S76), contains five genera three of which are due to him. Cyclosomus 

 Latr. which belongs here has a decided resemblance to Omophrvn, and 

 has very oddly place by various authors from an incorrect appreciation 

 of its true relationship which Chaudoir first made known. 



Among the genera dismembered from Tetragonoderus is Peronoscelis 

 Chd., which is said to differ from the former by the ligula not margined 

 in front by the extension of the paraglossae. In the dissection above 

 quoted the ligula and paraglossae have been drawn exactly as I have 

 observed them and there does not appear to be any extension of mem- 

 brane in front of the ligula, an appearance of this kind may, however, 

 be produced by disarranging the focus of the microscope and an optical 

 illusion is the result. From the failure of this character there may be 

 considerable doubt of the value of the genus. 



In the diagnosis of the two genera will be found the following 

 expressions : 



Tetragonoderus * * * unguiculi tenues, acuti, subtus obsoletissime basi, inter- 

 dura evidentius, denticulati. 



Pkronoscelis * * * unguiculi simplices, aut obsoletissime basi denticulati. 

 These extracts are introduced because certain of our species have 



