Nov., 1846.] 125 



an old genus, should generally be allowed to decide what portion 

 is to retain the old generic name. The rule which adopts as the 

 type the species which stands first in an author's work, is not 

 applicable in all cases, because these were not always considered 

 the type of the genus. An author might name a genus Geo- 

 trupes from the known habits of a European species, and com- 

 mence his list with a large exotic species having entirely different 

 habits, and not really congeneric with it. In such a case it would 

 be obviously improper to consider the latter as the type of the 

 genus Geotrupes. Moreover, instead of being the type, the 

 initial species may have been thus placed from its resemblance 

 to the preceding genus ; and it is obvious that the animal which 

 most nearly approaches another genus, cannot be the type of that 

 to which it really belongs. 



1. Brachycopris. The type of this new genus is the well 

 known Copris Carolina. In Copris the labrum is subquadrate, 

 rather widest anteriorly ; the anterior margin transverse, slightly 

 emarginate, with a medial projecting appendicle, and the ex- 

 terior margins rounded. In Brachico- 

 pris the labrum is distantly triangular, 

 widest at base, and much narrowed an- 

 teriorly, where it is deeply emarginate, 

 leaving a lateral aculeate process, the 

 appendicle projecting from the base of 

 the emargination, as represented in the 

 figure. The basal articulation of the 

 labial palpi is proportionally much 

 larger than in Copris. This body is con- 

 tracted in length ; and in the type, the elytra are sulcate and the 

 tibiae unarmed. 



Copris molossus would upon first view be placed nearer to C. 

 Carolina than to C. lunaris, or the American C. anaglypticus, 

 Say. Its labrum, however, associates it with these. Mr. Hope 

 has made it the type of his genus Catharsius. It has the labium 

 more regular, more nearly quadrate, and the anterior half only 

 of the medial solid portion is covered with hair, the posterior 

 portion presenting a smooth furrow with a well defined margin. 



2. Prionus fissicornis. General characters as in P. imbri- 

 cornis. Blackish brown, antennre thick, imbricate, reaching the 

 middle of the elytra, 25 articulate, canaliculate beneath by means 

 of a deep emargination in the articulations, which are somewhat 

 v-shaped when detached, the posterior branch the longer, with 

 its apex incurved: prothorax with three lateral teeth. 11 lines 

 long. 



For this interesting species I am indebted to my friend Dr. J. 

 L. Le Conte, who found it near the Rocky mountains. It is re- 



