40 



PROCEEDINGS OF THE NATIONAL MUSEUM 



Branchiobdellid associates include C. philadelphica at stations 17, 

 39, 44, 68, 115; C. holostoma at 7; B. illuminatus at 17, 44, 68, 115; 

 and Xg. instabilius at 44. 



Donnaldsoncy there truncata Hobbs and Walton 



Figure 96 



Donnaldsoncythere truncata Hobbs and Walton, 1963, pp. 364-366, 369, figs. 

 16-20, 24. 



Diagnosis. — Copulatory complex with peniferum terminating 

 ventrally in broad short terminal extension with subangular distal 

 corners; neither corner conspicuously thickened; clasping apparatus 

 with proximal shaft portion only slightly curved and distal third 

 directed at angle of about 90° to proximal third; internal border of 



Figure 9. — Penifera of entocytherids: a, Donnaldsoncythere scalis; b, Dn. truncata: 



c, Dactylocythere chalaza. 



distal fifth with six serrations, proximal three toothlike. Distal end 

 of penis situated above terminal extension rather than posterodorsal 

 to it as in other species of genus. 



Range. — Tributaries of the New and Roanoke Rivers in Mont- 

 gomery and Giles Counties, Va. 



Specimens examined. — Approximately 325 specimens from 17 

 collections from the following stations: 53-57, 69, 71, 87, 88, 90, 91, 

 93, 94, and 111. These are situated on tributaries to Walker Creek, 

 Spruce Run, and Toms Creek (New River drainage) and from tribu- 

 taries of the North Fork of the Roanoke River at elevations ranging 

 from 445 to 625 m. 



