SMITHSONIAN INSTITUTION. 



UNITED STATES NATIONAL MUSEUM. 



NOTES ON NORTH AMERICAN CRAYFISHES, 

 FAMILY ASTACID^E. 



WALTER FAXON. 



From the Proceedings of the United States National Museum, Vol. XII, pages 619-634. 

 [No. 785-] 



WASHINGTON; 



GOVERNMENT PRINTING OFFICE. 



