16 AMERICAN COLEOPTERA. 



tibijB, the presence of pubescence on the inner side of the posterior 

 tibije, and the existence of a fovea, groove, deep puncture, or punc- 

 tured area near the middle of the prosternum. They afford useful 

 means for the definition of subgenera, groups of species and species. 



Amard is included in the tribe Pterostichini as defined by Horn. 

 From the other genera of the tribe represented in our fauna, except 

 Evarthrus, it is distinguished by the form of the labial palpi, tlie 

 terminal joint of which is shorter than the penultimate, the latter 

 plurisetose in front. From Evarthrus it may be recognized by the 

 absence of a dorsal puncture on the elytra. Its geographical distri- 

 bution is very wide, extending over the whole of the Palsearctic and 

 Nearctic regions. A number of species are confined to high lati- 

 tudes and alpine regions. 



As now generally adopted its classification is based upon tlie 

 studies of Zimmermann, successively modified by those of LeConte, 

 Putzeys, Schaum, Horn and Ganglbauer. By the first named 

 author the genus was divided into eight groups, which were regarded 

 by him as genera, while by later authors they have been variously 

 treated as genera, subgenera or groups. 



Before passing to the study of our sjjecies, it may be remarked 

 that this paper lays no claim to be an exhaustive monograph of the 

 subgenera treated. Such a work wouhl be impossible without a 

 thorough study of foreign material and comparison of types. I 

 have merely attempted to present the results of my studies in such 

 form as to assist in tlie recognition of our species, and it is hoped 

 that a step has been made toward a rational arrangement of those 

 of which synoptic tables have not heretofore been published. In 

 the tables of those subgenera that have been studied by previous 

 writers, I have, of course, drawn largely upon their work, with such 

 mollifications as have seemed necessary. 



The genus, as represented in our fauna, may be divided into the 

 following subgenera, which may thus be defined : 



Prosternum marfrined at tip 2. 



Prosternum not margined at tip; prothorax wider in front of base; apical spur 

 of anterior til)ite simi)ie; bind tibia- not pubescent on the inner side 

 in the males. 

 .Middle tibiie dentate or bisinuate on the inner side in the males; form elon- 



git^e i. C'yrtoiiutii!<< Ste))!). 



Middle tibise simjile in i)oth sexes; form more robust. 



ii. LeironotiiM Ganglb, 



