624 NORTH AMERICAN ASTACIDE—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 bartonit and C. longulus are both found in Reed 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 « 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 River, Morgantown, North Carolina; Neuse River, 
Raleigh, 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 
Astacide. 
(i alae Cala sapeceen Amalie ly elie spdih 
Cambarus dubius Fax. (3 60 0 Q On.) 
Additional locality: ‘‘Among the Cherokees,”(ndian 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 Tsisgdagili (red crayfish) by 
the Cherokee Indians. 
Cambarus diogenes Gir. 
Additional localities: Prince William County, Virginia, Dr. H. 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 (U.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- 
