116 " A EE VISION OF THE ASTACID.E. 



tooth or projecting angle about midway from base to extremities; apical 

 formino: a very obtuse anajle with basal half." 



Female. — Fingers shorter than in the male ; annulus vcntralis with a 

 large tubercle on the posterior margin divided in the middle by a longitu- 

 dinal sinuous line, anterior border bituberculate, fossa deep, transverse. 



Measurements of a male, form II. — Length, 70 mm. Cephalothorax, 35 

 mm. Abdomen, 35 mm. From tip of rostrum to cervical groove, 24 mm. 

 From cervical groove to posterior border of telson, 10 mm. Length of 

 rostrum, 11 mm. Width of rostrum, 4.5 mm. Length of acumen of ros- 

 trum, 5 mm. 



Knotvn Localities. — South Carolina: Saluda River (Coll. Butler Univ.). 

 Georgia : neighborhood of Rome (Etowah, Oostenaula, and Coosa Rivers). 

 Tennessee River near border of Georgia. Alabama : Cypress Creek, Lau- 

 derdale Co. 



The specimens described by Bundy were collected in the neighborhood 

 of Rome, Ga., by Prof D. S. Jordan. Some of these specimens have been 

 communicated to me by Prof. 0. P. Hay, of Butler University, Irvington, 

 Ind., and Mr. P. R. Uhler, of Baltimore, Md. They embrace males of the 

 second form, females, and young. According to Bundy, only one out of the 

 nineteen specimens examined by him was a male of the first form. 



In general appearance this species resembles C. (iffinis, but differs in 

 being smoother, in the shortness of the carapace behind the cervical groove, 

 the single lateral spine, the absence of spines on the hej^atic region, emar- 

 ginate epistoma, longer antennte, and in the form of the male appendages, 

 which resemble those of C rusiicus and C. obscunis. In these, however, tlie 

 male appendages are shorter, and the rami are shorter relatively to the 

 length of the whole appendage. 



The female specimen from the Tennessee River near the borders of 

 Georgia, mentioned by Hagen under C. extraneiis as resembling C. affinis, 

 belongs to this species. Jordan also found C. spinosus in company with 

 C. extnmeus in the rivers explored by him in the neighborhood of Rome, 

 Georgia. 



In the collection of Butler University is a single female C. spinosus, col- 

 lected by Jordan in the Saluda River, South Carolina. In this specimen the 

 posterior section of the carapace is a little longer than in the Georgian types, 

 the distance from the cervical groove to the posterior border of the cara- 

 pace being equal to half the distance from the groove to the middle of the 



