Procambarus, a New Subgenus. 437 



in this case, but tuberculiform, belongs to the inner part. (Compare 

 also Faxon's figure of C. carinatits = digueti, Proc. U. S. Mus. 20, 

 1S98, pi. 63, f. 2.) 



Thus this organ is fundamentally different from that of the subgenus 

 Cambarus d& represented by its type ( C. d/andi/igi), and, moreover, 

 it possesses at its anterior margin, not far from the tip, a peculiar 

 angular projection, which I have called the " shoulder." Such a 

 shoulder is found in a few cases in other species belonging to the sub- 

 genus Cambants ( C. clarki and troglodytes^ , and in numerous species 

 of the subgenus Faxonius (section of C. propiiiquus); but here it 

 always has a different position, being quite remote from the tip of this 

 organ. 



Thus I think we are justified in emphasizing this peculiar feature of 



the male organs by creating for it a separate subgenus, for which the 



name Frocatiiban/s is proposed, and we consequently have now Jive 



subgenera within the genus. The diagnoses of the two first are as 



follows. 



Procambarus subgen. nov. 



Sexual organs of male stout, more or less straight and comparatively 

 short, rather blunt at the end, but not truncate. The two parts in 

 fci close Opposition up to the tips. The outer one ending bluntly, with- 

 out h^rny teeth ; the inner one being more or less similar to the outer 

 one, but possessing in various positions one horny spine. Anterior 

 margin with a shoulder near the tips. In the male the third pereiopods 

 have hooks. 



Species : digueti, lailliainso/ii, inexica/ucs, ciibensis. 



Cambarus (Ortmann sens, restrict'). 



Sexual organs of male stout, more or less straight and comparatively 

 short, very blunt, or truncated at the end. The two parts in close 

 ' (X. Opposition, with exception of the terminal spines. The outer part 

 ending in one to three horny teeth, which are often recurved, or com- 

 pressed, or plate-like, being sharply distinguishable from the blunt 

 end. Inner part terminated by a shorter, or longer, acute spine. A 

 shoulder on the anterior margin is rarely present, and it is, if present, 

 quite remote from the tip. In the male the third, or the third and 

 fourth, pereiopods have hooks. 



The diagnoses of the other three subgenera : Cainbarellits, Faxonius, 

 Bartonius, do not require any change. 



