no. 3602 CRAYFISHES — HOBBS, HOLT, AND WALTON 41 



Hosts and associates. — In the Roanoke River drainage, Dn. 

 truncata was associated with Cambarus acuminatus at stations 87, 

 88, 90, 91, 93; with C. b. bartonii at 87, 90, 91, 93, 111; and with C. I. 

 longulus at 88, 90, 91, and 93. In the New River drainage, it was 

 with C. b. bartonii and C. sciotensis at 54 and 57; with the former 

 at 53, 69, 71, 94; and with C. sciotensis at 55 and 56. 



Ostracod associates include Dt. falcata at stations 87, 88, 90, 

 91, 93, 111; An. ancyla at 88, 93; E. internotalus at 88, 90; Dn. ileata at 

 54-57, 69, 71, and 94. No ostracod associates were with it at 53. 



Branchiobdellid associates include C. philadelphica at stations 

 53-56, 69, 71, 87, 88, 90, 91, 93, 94, 111; A koronaeus at 69, 71, 

 87, 88, 90, 91, 93, 111; C. branchiophila at 55, 57, 87, 88, 90, 91, 

 93; C. fallax at 54-57, 71, 87, 88, 91; Xd. jormosus at 88, 90, 91; 

 Xg. instabilius at 53, 54; B. illuminatus at 87; and C. ingens at 54. 



Genus Dactylocythere Hart, 1962 



Diagnosis. — Copulatory complex with finger guard; two rami of 

 clasping apparatus never forming angle greater than 90° and usually 

 (except in Dt. striophylax Crawford and Dt. falcata Hobbs and Walton) 

 bearing teeth or serrations on internal border; peniferum provided 

 with accessory sperm groove but never terminating in "barbed 

 terminal extension" (Hart, 1962, p. 129). Females with J-shaped rod 

 (except in Dt. leptophylax Crawford) and amiculum; claws of second 

 antenna simple. 



Dactylocythere chalaza (Hobbs and Waltou) 



Figures 7e, i, 9c 



Entocythere chalaza Hobbs and Walton, 1962, p. 45, figs. 6~9- 

 Dactylocythere chalaza Hart, 1962, p. 129. 



Diagnosis. — Posteroventral margin of shell without conspicuous 

 prominence. Accessory groove extending dorsally to level of spermatic 

 loop; clasping apparatus with junction of horizontal and vertical rami 

 forming angle of less than 90°, distinctly thickened at junction, 

 and internal border of horizontal ramus with single tooth and three 

 distal serrations. Female with J-shaped rod and amiculum. 



Range. — Drainage systems of the James and New Rivers in 

 Craig and Giles Counties, Va., and Monroe County, W. Va. 



Specimens examined. — Approximately 775 specimens in 12 collec- 

 tions from the following stations: 8, 22, 40, 41, and 127, at elevations 

 of 585 to 1250 m. 



Hosts and associates. — Dactylocythere chalaza, like As. asceta, 

 seems to be restricted to a single host Cambarus carolinus. 



