624 NORTH AMERICAN ASTACID^ — FAXON. 



Girard did not know whence his type of C. longulus came. As far 

 as known it is found in the elevated parts of Virginia, West Virginia, 

 western North Carolina, and eastern Tennessee, drained by the Shen- 

 enandoah, James, Kanawha, and Holston river-systems. It is thus 

 found on both sides of the Appalachian water-shed. 



Cambarus bartonii and C. longulus are both found in Eeed Creek at 

 Wytheville, Virginia, with no indication of the two forms interbreeding. 

 But it is not on this account that I consider them two species. I have 

 reason to believe that oftentimes in this genus mere varieties, coming 

 into contact in a given locality, are perpetuated by breeding true, 

 when, by extending our geographical range, every intermediate con- 

 dition connecting the two forms will be found still surviving. Nowhere 

 do we seem to come so near to seeing the process of evolution of species 

 going on under our very eyes as in this genus Cambarus. It seems to 

 me that the only criteria of a species must be the amount and character 

 of the variation, and the absence of intermediate forms not in one 

 locality alone but over the whole area of distribution. 



Cambarus acuminatus Fax. 



Additional localities: Swannanoa River, Black Mountain, North 

 Carolina; James Biver, Morgantown, North Carolina; Neuse Biver r 

 Baleigh, North Carolina; Reedy Fork, Cape Fear River, Greensborough, 

 North Carolina. D. S. Jordan (U. S. F. C). 



The specimen (a female) from Morgantown agrees with the type of 

 C. acuminatus from the Saluda River, South Carolina, in the lack of a 

 suborbital spine. In the others this spine is present as in the North 

 Carolinian specimens mentioned on page 68 of the Revision of the 

 Astacidse. 



Cambarus dubius Fax. 



Additional locality: "Among the Cherokees," Indian Territory. One 

 male, form I. James Mooney (U. S. N. M.). 



This species was previously known only from the remote Appalachian 

 Mountain region of Virginia and West Virginia. According to the 

 label accompanying the specimen it is called Tsisgdgili (red crayfish) by 

 the Cherokee Indians. 



Cambarus diogenes Gir. 



Additional localities : Prince William County, Virginia, Dr. fl. C. 

 Yarrow ; Kankakee River, Riverside, Indiana, C. H. Gilbert ; Kokomo, 

 Indiana, A. W. Moore (U. S. N. M.). 



Cambarus argillicola Fax. 



Additional locality: Lowlands bordering on Wabash River, York, 

 Clark County, Illinois. H. G. Hodge (IT. S. N. M.). 



According to the manuscript label accompanying these specimens, 

 they were found in burrows from 18 inches to 2 feet in depth, contain- 



