22 



PROCEEDINGS OF THE NATIONAL MUSEUM 



chasmodactylus 

 2.2 

 1.9 

 0.69 



1. 1 

 LO 

 3.5 

 6.0 

 4.4 

 0.34 

 0.47 

 0.37 

 L6 

 2.7 



2. 2 

 0.48 

 0.74 

 0.61 

 2.6 

 4.7 

 3.6 

 L2 



Summary 



As a result of the present study, three allopatric subspecies of 

 Camharus longulus Girard have been recognized. Camharus longulus 

 longulus is found in the lower mountain and piedmont streams of 

 the Atlantic drainage, from the James south to the Yadkin Rivers. 

 Camharus longulus chasmodactylus, herein described, is restricted to 

 the New River system from North CaroHna to western West Virginia. 

 Camharus longulus longirostris frequents the Tennessee drainage 

 system above Wilson reservoir, and the Coosa River drainage in 

 northwestern Georgia and eastern Alabama. 



Although aU three subspecies are associated with riffle areas of 

 lotic habitats, C. longulus longirostris appears to have a broader 

 ecological tolerance than do the two other subspecies. 



While C. I. chasmodactylus exhibits few variations throughout its 

 range, C. I. longulus, perhaps because of its low vagiUty, has within 

 its range several recognizable local populations. 



It is concluded that these three crayfishes represent offshoots 

 of a common stock which, while beheved to be not too far removed 

 from the primitive members of the genus, have become, for the most 

 part, ecologically, highly speciaUzed for Ufe in restricted areas of 

 "young" but not "infant" streams. 



