36 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



comparatively slender, with subterminal bulbous enlargement bearing one 

 (anterior) or several projections; penis complex consisting of separate dorsal 

 spermatic and ventral prostatic elements; spermatic element always shorter than 

 clasping apparatus; accessory groove lacking. Clasping apparatus well developed, 

 not always clearly divisible into vertical and horizontal rami; external border of 

 horizontal ramus entire, internal border with two, three, or no teeth along apical 

 half, if present often grouped far distally with three apical denticles. 



Ascetocythere asceta (Hobbs and Walton) 



Figures 7c, 8a 



Entocythere asceta Hobbs and Walton, 1962, pp. 43-44, figs. 1-4. 

 Ascetocythere asceta Hart, 1962, p. 128. 



Diagnosis. — Hobbs and Hart (1966, p. 39) stated: 



Peniferum with three prominences extending from subterminal bulbous expan- 

 sion — anterior process delicate, club-shaped, extending anteroventrally, from 

 cephalic surface; ventral process large, finger-like, with distinct angular flange 

 near its midlength, and directed ventrally; posterior process small, rounded, and 

 situated at posterior base of ventral process; prominent penis guide (acute pro- 

 jection) lying between flange and anterior process; penis reaching surface anteriorly 

 dorsal to flange. Vertical ramus of clasping apparatus less than % of total length 

 of apparatus; internal border of horizontal ramus with two teeth along distal third 

 with distal tooth almost midway between proximal tooth and apex. 



Range. — Known from crayfish burrows in the James and New 

 river systems in Craig and Giles Counties, Va., and from Monroe 

 County, W. Va. 



Specimens examined. — 275 specimens in 12 collections from the 

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

 1250 m. 



Host and associates. — Ascetocythere asceta is apparently restricted 

 to the single host Cambarus carolinus. 



Ostracod associates include but one species, Dt. chalaza, with which 

 it was found in all five localities. 



Branchiobdellid associates include B. illuminatus at stations 40, 

 41, and 127; and C.fallax at 40. 



Genus Donnaldsoncythere Rioja, 1942 



Diagnosis. — Copulatory complex without finger guard; clasping 

 apparatus frequently not divisible into vertical and horizontal rami 

 and angle formed by extensions of two always greater than 90°; 

 external border of horizontal ramus (or distal half of apparatus) 

 entire and internal border never with more than three teeth near 

 distal end, distal extremity terminating in from 3 to 10 serrations or 

 emarginations ; peniferum lacking accessory groove; corneous penis 

 curved at almost right angle near midlength with proximal extremity 

 level, or almost level, with base of clasping apparatus. Length of 



