no. 3602 CRAYFISHES — HOBBS, HOLT, AND WALTON 57 



97, 122, 123, 125; with C. L longulus at 34, 123; with C. sciotensis at 3, 

 5, 61, 63-67, 70, 72, 78-81, 86, 97, 105, 106, 116, and 126. 



Ostracod associates include Dn. ardis at station 123; Dn. ileata 

 at all stations except 70 and 78; Dt. daphnioides at 70, 72, 79-81, 

 116; £7. kanawhaensis at 126; and P. phyma at 3, 5, 24, and 64. 



Branchiobdellid associates include A koronaeus at stations 72, 125; 

 A. legaeus at 81; B. illuminatus at 5, 34, 45, 48, 86, 97, 122, 125; 

 C. branchiophila at 24, 63, 65-67, 72, 79, 81, 86, 97, 116, 126; C.jallax 

 at 3, 5, 24, 61, 63, 65-67, 70, 72, 78, 79, 81, 86, 97, 126; C. ingens at 5, 

 61, 64, 67, 70, 72, 79-81, 86, 97, 116; C. philadelphica at 3, 5, 24, 28, 

 34, 45, 48, 66, 106, 122, 123, 125; P. alcicornus at 3-5, 24, 61, 63-67, 

 70, 72, 79, 81, 86, 97, 105; and Xg. instabilius at 3-5, 24, 61, 64, 86, 

 97, and 123. 



Remarks. — The absence of C. heterognatha in our collections from 

 the Roanoke drainage is surprising; but the species, in our experience, 

 is predominantly one of tributary streams of the mountains and most 

 of our collections from the Roanoke were from regions of lower 

 gradient and fair volume of stream flow. There exists (Hoffman, 

 1963, p. 364) a record of C. heterognatha from Franklin County, Va., 

 which is within the Roanoke River system. Only a more detailed 

 analysis of the distribution of the species will enable a decision to be 

 made as to whether the species is just now, at some favorable areas of 

 stream capture, invading the Roanoke or whether the distribution as 

 known is determined by local stream conditions. 



Cambarincola holostoma Hoffman 



Figures 17 a-d 

 Cambarincola holostoma Hoffman, 1963, p. 359. 



Diagnosis. — Peristomiuni entire without lobes or tentacles; 

 prosomites not of greater diameter than metasomites; dental formula 

 3/3; reproductive systems similar to those of C. philadelphica. 



Range. — Cambarincola holostoma is known only from western 

 Virginia in the headwaters of the Potomac and James Rivers with an 

 isolated occurrence in Sinking Creek (sta. 18, 19) of the New River 

 drainage. 



Specimens examined. — Approximately 80 specimens in 12 collec- 

 tions from the following stations: 7, 10, 11, 13, 18-23, 25, and 37. 

 These stations are in the James River drainage (Potts, Johns, and 

 Craig Creeks) except 18 and 19 which are in the New River drainage 

 (Sinking Creek). The elevations of these stations range from 512 to 

 671 m. 



Hosts and associates. — Cambarincola holostoma was associated 

 with Cambarus acuminatus at station 20; with C. b. bartonii at 7, 10, 



