20 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 119 



(Virginia)"; and those "near White Sulphur Springs, Greenbrier Co., 

 West Va." (1885a, pp. 60, 61) as C. I. chasmodactylus. 



While C. I. longulus is the most variable of the subspecies, C. I. 

 chasmodactylus appears to be the most stable. Little or no differences 

 occur between even mdely separated populations. One exception is 

 the collection of nine specimens from Carroll County, Va., in which all 

 juveniles and adults (as well as males and females) possess strong 

 lateral spines on the carapace. This collection (map 2, no. 240) was 

 made in a tributary of Crooked Creek (New River drainage). All 

 other specimens including those from Reed Island Creek, an adjacent 

 tributary to the New River, lack these lateral spines. Additional 

 collecting in this area wiR be necessary before further comment may 

 be made. 



The largest available specimen of C. I. chasmodactylus is a female 

 \dth a carapace length of 55 mm.; the largest chela I have seen 

 measiu-es 78 mm. in length by 26.5 mm. in width; only the hand of 

 this animal is available. Size, however, must be disregarded as a 

 diagnostic featm^e since many fu'st-form males have a carapace length 

 as little as 30 mm. and, as noted, the largest first-form male of 0. I. 

 longulus (the smallest of the subspecies) is 34 mm. 



Specimens examined. — I have examined approximately 275 speci- 

 mens in 56 collections from 44 localities; all are confined to the New 

 River drainage system of North Carolina, Vhginia, and West Virginia. 



Entirely confined to the New River system, the known range of 

 C. I. chasmodactylus extends northward to the upper reaches of the 

 Greenbrier River in West Vhginia (map 2, nos. 261-268); the most 

 southern record is from Watauga County, N.C., in the headwaters 

 of the South Fork of the New River (map 2, no. 229). Both eastern 

 and western boundaries are formed by those Appalachian Mountains 

 delimiting the New Valley. 



There appears to be complete geographic isolation between this 

 and the other two subspecies. In Alleghany County, N.C. (map 2, 

 no. 215), C. I. chasmodactylus was collected from a tributary of the 

 New River only a few mUes from where C. I. longulus was collected 

 in the Yadkin drainage in Wilkes County (map 2, no. 105), but 

 nowhere in the entire range is there evidence of sympatry. 



Ecological Distribution 



The general habitat of the species Cambarus longulus has been 

 noted by various investigators (Ortmann, 1913, pp. 375, 376; 1931, 

 pp. 119, 123; Hobbs, 1950, p. 349; Reid, 1961, p. 249). Members of 

 C. longulus are highly restricted stream or river mhabitants that 

 live under or between rocks, away from the shore, in moderate to 

 swiftly flowing, cool to cold water. The species does not, from all 



