no. 3602 CRAYFISHES — HOBBS, HOLT, AND WALTON 23 



and Kentucky. At least two color phases are involved, and perhaps 

 two or more races should be recognized. 



Specimens examined. — 135 specimens in 12 collections from the 

 following stations: 8, 22, 40, 41, and 127, at elevations of 585 to 1250 

 meters. Three of these lie in the New and two in the James drainage 

 systems. 



Associates. — Cambarus carolinus was collected with no other 

 crayfish, for it is the only primary burrowing species in the area. 

 There is little likelihood of its being found with any other species in 

 the region except possibly C. b. bartonii. 



Ostracod associates include As. asceta and Dt. chalaza, which have 

 been found with no other crayfish except C. carolinus and which were 

 with it in all five of the localities in which it was collected. 



Branchiobdellid associates include B. illuminatus and C. fallax at 

 station 40, and only the former at 41. 



Remarks. — While our knowledge of all of the crayfishes in the 

 region is limited, data on C. carolinus is almost totally lacking. The 

 rocky soil in the area makes digging for these animals highly impracti- 

 cable, and most of our specimens were collected on foggy or rainy 

 evenings when the crayfishes had left then' burrows and were crawling 

 about in the grass on the golf course (sta. 41) and in the road (sta. 40). 



Cambarus carolinus seldom invades bodies of open water. In some 

 12 years of observing the streams in the area, we have seen only one 

 individual (juvenile) in such a habitat — at Hunters Branch on the 

 grounds of the Biological Station one evening following a heavy rain. 



Several attempts to extricate individuals of this species from bur- 

 rows in the vicinity of the Mountain Lake Biological Station proved 

 totally unsuccessful. The same technique used there, however, was 

 most successful in a cleared, grass-covered area near the junction of 

 White Rock Branch and Big Stony Creek (sta. 127). Taking care 

 not to allow the burrow to become clogged with earth, a shovel was 

 used to open the burrow to the water table, and the water was 

 thoroughly roiled. Within a short time, the crayfish came to the 

 exposed area and its antennae could be seen whipping to and fro just 

 below the surface film. Making a quick grab, the observer caught 

 the animal. In the area of the Biological Station, the crayfish were 

 never observed coming to the exposed opening as they character- 

 istically did here. 



The depths of the burrows at station 127 were not determined, but 

 at about 60 cm below the surface some of them contained chambers 

 15 to 20 cm in diameter. From one large chamber, 12 juveniles 

 (with carapace lengths ranging from 11 to 18 mm) and an adult 

 female, presumably the mother, were taken. 



