442 Annals of the Carnegie Museum. 



genus, chiefly from the typical subgenus Cambanis, renders the Mexi- 

 can crayfish-fauna rather peculiar. In Mexico, two well known sub- 

 genera are represented : Procambarus and Canibarelli/s. The first 

 one has no representatives at all in the United States, while Cam- 

 barelliis has only one (in Louisiana). There remains a Mexican 

 species, C. 7tnegmanni, which has been placed with species of the true 

 subgenus Cainbai'iis, but its position is quite uncertain, the male 

 copulatory organs being unknown. 



Carnegie Museum, 

 June lo, 1905. 



