CRAYFISHES — HOBBS, HOLT, AND WALTON 



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Table 1. — Summary of geographical and altitudinal distribution and associations 

 of the crayfishes, entocylherids, and branchiobdellids of the Mountain Lake Region 

 (J — James; N = New; R= Roanoke) — Continued 



Georgia and confined to the New River and its tributaries in the area, 

 is another specialized offshoot of the C. philadelphica stock that has 

 reached the Mountain Lake region from the south. There is one 

 record from Patrick County, Va., in the Roanoke drainage (Hoffman, 

 1963, p. 335) ; the remaining records from outside the area are from 

 the mountain streams of the New and Tennessee drainages. Cam- 

 barincola ingens is a Blue Ridge species, but it is impossible to decide 

 whether it evolved in the headwaters of the New River in North 

 Carolina or in those of the Tennessee River in the same region. 

 Cambarincola heterognatha is known from the Potomac southeastward 

 through the mountains in the New, Cumberland, and Tennessee river 

 systems, with one isolated record in the Roanoke drainage (Franklin 

 County, Va.). Again, we are dealing with a species, widespread in the 

 mountains, that appears to have spread into the Tennessee drainage. 

 The alternative possibility of an origin in the Tennessee may be as 

 likely, and there is no way now to decide between these choices. 

 Finally, C. fallax is not quite so widespread as C. philadelphica, but it 



