PROCEEDINGS 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. VIII, pp. 1-24. May 3, 1906. 



MEXICAN, CENTRAL AMERICAN, AND CUBAN 



CAMBARI. 



By A. E. Ortmann, 

 Carnegie Museum, Pittsburg, Pa. 



The larger part of the material, upon which the following 

 notes are based, was loaned to the writer by the Museum of 

 Natural History of Paris through the kindness of Professor E. 

 L. Bouvier, for which I wish to express my most sincere thanks. 

 I am also under obligations to the Academy of Natural Sciences 

 of Philadelphia, where I was granted the privilege of examin- 

 ing the crawfish-collections ; some of this material has also been 

 used for the following notes. 



I. Subgenus PARACAMBARUS, new subgenus. 



Paracambarus, new subgenus of Potamobiidas ( Cambarus 



■paradoxus ) . 



Sexual organs of male with the two parts in close apposition 

 to their tips ; in the male of the first form, both tips are shortly 

 pointed and horny ; in addition there is, on the posterior margin 

 of Ire inner part, at a short distance from the tip, a long and 

 strong, horny spine. Anterior margin of sexual organs with- 

 out shoulder. Male with hooks on the ischiopodite of fourth 

 perciopods only. Female with a spin form process on the 

 sternum between the fifth perciopods. 



The presence of hooks only on the fourth pereiopods of the 

 male, and the peculiar spine of the sternum of the female dis- 

 Proc. Wash. Acad. Sci., May, 1906. 1 



