72 



Julian J. Lewis 



Fig. 4. Pleopod 1 of male Caecidotea: (a) Caecidotea bicrenata, Mystic River, 

 Mammoth Cave, Edmonson Co., KY; (b) Caecidotea bicrenata whitei, Mill 

 Hole, Barren Co., KY; (c) Caecidotea bicrenata bicrenata, Beech Spring Cave, 

 Marshall Co., AL. 



other populations exhibiting this modification of the second pleopod, 

 such that if hybridization is occurring it is across a rather wide geogra- 

 phic range. In isopods from other rivers flowing through the Mammoth 

 Cave System that have been sampled, the lateral process is present. In 

 the absence of the lateral process, critical in identifying specimens to the 

 subspecific level, these populations are here identified only as Caecido- 

 tea bicrenata. 



Caecidotea bicrenata (Steeves) 

 Material examined. — TENNESSEE: Dickson Co., stream in 

 Columbia Caverns, 2 mi. SW VanLeer, 22 June 1957, L. Hubricht, 

 4$$, 3$$. Macon Co., Ann White Cave, 6 mi. W Lafayette, 19 Apr 

 1958, L. Hubricht, 9$$, 7§9. Montgomery Co., Dunbar Cave, 1.5 mi. 

 S St. Bethlehem, 15 June 1957, L. Hubricht, 13<3<3, 1$. KENTUCKY: 

 Edmonson Co. , Mammoth Cave National Park, Mammoth Cave, Mys- 

 tic River near Mystic River tributary, 27 Dec 1981, J. Lewis, T. Lewis, 

 J. Eckstein, T. Leitheuser, 5<5<?. 



