38 A REVISION OF THE ASTAl ID.K. 



cillatus by Hagen, and the two can hardly belong to the same species. The 

 teeth at the tip of the external part are also shorter and blunter in the 

 Mississippi specimen than in those from Charleston. The hooks on the third 

 and fourth pairs of thoracic legs are very small. — mere tooth-like processes. 

 The antennal scale is broad at the tip, as in the Georgia specimen. 



Measurements. — Length, 50 mm. Carapace, 25 mm. Abdomen, 26 mm. 

 Rostrum, 5 mm. From tip of rostrum to cervical groove. 16.5 mm. Car- 

 diac region, 8.5 mm. Width of areola, .5 mm. Length of chela, 14 mm. ; 

 breadth of chela, 5 mm. 



This specimen, as well as those from Charles! on, may belong to different 

 species from C. penicillatus, but my material is not sufficient to warrant the 

 establishment of new species. 



Le Conte does not specify from what part of Georgia his specimens came, 

 nor is the locality of the Georgia specimens in the Museum of Comparative 

 Zoology any more precisely indicated. 



14. Cambarus Wiegmanni. 



Astacus {Cambarus) Wiegmanni, Erichson, Arch. f. Natrirgesch., XII. Jahrg., I. 99, 1848. 



Wiegmanni, Hagen, 111. Cat. Mus. Comp. Zool., No. III. p. 54, PI. III. fig. 151, 1870. 

 Cambarus Wiegmanni, Faxon, Proc. Ami-r. Acad. Ails ami Sri., \\. 138, L884. 



Four species of Cambarus have been described from Mexico; viz. C. Wieg- 

 manni Erichs., C. Mexicanus Erichs., C. Azfccv* Saussure, and C Montezumce 

 Saussure. C. Wiegmanni lias hooks near the base of the third and fourth pairs 

 of legs of male, tuberculated chelas, carpus dentated on the inner border. 

 ('. Mexicanus lias only the third pair of legs of the male hooked, chelae 

 granulated, carpus unarmed. C Asiecus also has the third pair of legs 

 hooked in the male, chela- granulated, more compressed than in C. Mexi- 

 canus, carpus armed with some spines within and below. It is doubtful 

 whether this he specifically distinct from C. Mexicanus. In ('. Montesumai 

 the second and third pair of legs of the male are hooked, the carpus and 

 chela- smooth. To the list of Mexican Cambari is to he added C immunis, 



collected at Orizaba by Prof. Sumichrast. An undescribed Parastacine occurs 

 at Colima, on the west coast. 



The types of Erichson's two Mexican species of Cambarus, C. Wiegmanni 

 and C. Mexicanus, could not he found in the Berlin Museum, either by Hagen, 

 who examined the collection in September, L870, or 1>\ Von Martens (Arch. 

 Naturgesch., 1872, p. 131). C. Wiegmanni alone of the known Mexican spe- 



