MEXICAN, CENTRAL AMERICAN, AND CUBAN CAMBARI 1 9 



not be surprised, if this latter species, of which the male is un- 

 known, should finally prove to belong to this group, and not to 

 the second group of Faxon (affinity of C. cubcnsis) as Hay is in- 

 clined to believe. 



The hooks of the ischiopodites of the pereiopods are very pecu- 

 liar, and unlike anything else that is known in the genus. And 

 further, the development of the spines and processes of the cox- 

 opodites of the three last pairs of pereiopods is very unique ; 

 such processes are indeed found in other species in the shape of 

 tubercles or ridges on the fourth or fifth pereiopods, but they 

 never assume such proportions as in this species, and the out- 

 wardly directed spine of the coxopodite of the fourth pereiopod 

 in C. wiegmanni is without parallel. 



Thus it seems that C. wiegmanni is to be regarded as a very 

 peculiar, and, in certain features, extremely developed form of 

 the subgenus Cambarus, which belongs to a rather advanced 

 and modern group of it (a l/cni- group, see 1. c, p. 105) which 

 is characteristic for those parts of the coastal plain of the south- 

 ern United States, that are most recent geologically. Its pres- 

 ence in Mexico is rather interesting, and the specialized char- 

 acter points to a recent immigration into these parts. But we 

 are to bear in mind that the a/lcni-gvoup in general is compara- 

 tively poorly known and needs further study. 



VI. Subgenus CAMBARELLUS. 



For the species of this subgenus I am only able to add a few 

 new locality records : 



Cambarus (Cambarellus) montczumce Saussure (Faxon, 1885, 

 121 ; 1898, 660). 



Neighborhood of City of Mexico : Laguna de Santa Isabel. 

 — G. Seurat coll., 1897 (Mus. Paris, 1 c? (I), 1 ?). 



Mexico. — Mus. Paris, numerous specimens, collected by 

 various persons, but without more explicit localities. 



Lake Xochimilco, south of City of Mexico (Federal Dis- 

 trict). E. D. Cope coll., 1885 (Philadelphia Academy, 1 ?). 



Most of the specimens seen by the writer belong to the form 

 tridens v. Mart. With Faxon, I do not believe that this is 

 worth a varietal name. According to my observations, young 



