ORTMANN 



cies given by Erichson, and the discription of the female given 

 by Hagen, there is hardly any difference. Hagen describes 

 and figures the epistoma as triangular and rather acute, which is 

 not the case in our individual, and further, Hagen gives only 

 two lateral spines for the anterior section of the telson. These 

 differences are of no consequence, variations in these charac- 

 ters being frequent in other species. I have compared the 

 female in Philadelphia, which served as the base of Hagen's 

 description, and which, since the Berlin types of Erichson have 

 disappeared, must be regarded as the type of the species, and 

 I find it to agree in all essential characters with our male, 

 chiefly so in the shape of body and rostrum. Thus I think, 

 the present male ought to be referred to this species. 



As is evident from the characters of the male of the first form 

 described above, C. wiegmanni belongs to the subgenus Cam- 

 barns, to the section of C. blandingi, and the group of C. 

 allem', 1 and it has been assigned its correct position already by 

 Hagen and Faxon (allied to C. barbatus). The sexual organs 

 are peculiar on account of the crescentic, compressed and trun- 

 cated outer horny tooth, and do not closely agree with any of 

 the known species of the subgenus ; but just this feature agrees 

 with the rt//£«z-group in so far as this group is characterized by 

 peculiar and aberrant conformations of the tips of the sex- 

 ual organs. 2 In shape of carapace, areola and rostrum, this 

 species agrees closely with C. evermanni, barbatus and alleni> 

 and the rostrum represents a rather advanced stage of develop- 

 ment, being broadly lanceolate, without any traces of marginal 

 spines or even marginal angles in their place. It resembles to 

 a certain degree, the rostrum of C. clyfeatus Hay 3 from Bay 

 St. Louis, Hancock Co., Miss., but in the latter form the rostrum 

 is still broader, and almost rounded off at the apex. I should 



1 See Ortmann, Proc. Amer. Phil. Soc. 1905, 98 and 100; Ann. Car. Mus., 

 I9°5. 437 and 438. 



2 The sexual organs agree most nearly with those of C. hinei Ortm. from Lou- 

 isiana, with the exception that in the latter species the crescentic and truncated 

 tooth is absent, and that the distal part of the organ is distinctly curved backward. 

 See Ortmann in The Ohio Naturalist, VI, 1905, p. 402, fig. 1. Also the rostrum 

 of C. hinei is transitional toward C. wiegmanni. 



3 Proc. U. S. Nat. Mus., XXII, 1S99, 122, fig. 2, no. 1. 



