no. 3602 CRAYFISHES — HOBBS, HOLT, AND WALTON 35 



10(8') Distal extremity of peniferum acuminate Dn. ardis 



10' Distal extremity of peniferum truncate, rounded, or scooplike ... 11 



11(10') Distal extremity of peniferum scooplike Dn. scalis 



11' Distal extremity of peniferum truncate or rounded 12 



12(11') Distal extremity of peniferum truncate Dn. truncata 



12' Distal extremity of peniferum rounded Dn. ileata 



Genus Ankylocythere Hart, 1962 



Diagnosis. — Copulatory complex without finger guard; extensions 

 of two rami of clasping apparatus never forming angle greater than 90° 

 and bearing one or more teeth or excrescences on both internal and 

 external borders of horizontal ramus; peniferum without accessory 

 groove, variable, sometimes cleft distally but never with bulbous 

 terminal or sub terminal enlargement. Females without J -shaped rod, 

 amiculum, or other comparable structure; claws of second antenna 

 simple. 



Ankylocythere ancyla Crawford 



Figure 7g 

 Ankylocythere ancyla Crawford, 1965, pp. 148-149, figs. 1-3, 6, 7. 



Diagnosis. — Horizontal ramus of clasping apparatus with single 

 tooth on internal border proximal to midlength and talon arising from 

 external border much proximal to tooth on internal border; talon 

 extending distally subparallel to ramus with tip reaching level just 

 distal to tooth; ramus terminating in two upturned teeth; distal 

 extremity of peniferum directed ventrally and shallowly excavate. 



Range. — From the Savannah River drainage in South Carolina to 

 the Roanoke River drainage in Virginia. 



Specimens examined. — 60 specimens in eight collections from the 

 following stations: 88, 89, 92, and 93. All localities are in the North 

 Fork of the Roanoke River drainage, at elevations of 439 to 475 m. 



Hosts and associates. — Cambarus acuminatus and C. I. longulus 

 were associated with this ostracod in all stations, and C. b. bartonii 

 was also present at stations 89, 92, and 93. 



In all stations Dt. falcata was present, and at stations 88 and 93 

 An. ancyla was also collected with Dn. truncata and at station 88 with 

 E. internotalis. 



Branchiobdellid associates include A. koronaeus, C. branchiophila, 

 C. philadelphica at stations 88, 89, 92, 93; and C. jallax and Xd. 

 formosus at 88, 89, and 92. 



Genus Ascetocy there Hart, 1962 



Diagnosis. — Hobbs and Hart (1966, p. 37) stated: 



Terminal tooth of mandible with cusps. Copulatory complex without finger 

 guard; peniferum extending ventrally much beyond clasping apparatus, elongate, 

 244-775 — 67 4 



