UPPER TENNESSEE DRAINAGE. 543 



But the specimens from the Holston drainage are not so well and 

 typically developed as those from the upper Clinch. 



Type locality: "Clinch River, Lee Co., Va." A case of inexcus- 

 able carelessness, for the Clinch never touches that county. 



Genus: Rotundaria Rafinesque (1820). 

 Ortmann, 1912&, p. 257. 



19. Rotundaria tuberculata (Rafinesque), 1820. 



ObUqnaria tuberculata Rafiesque, '20. — Unio verrucosus Lewis, 

 '71. — Unio verrucosus Pilsbry & Rhoads, '96, — Rotundaria tuber- 

 culata Ortmann, '12b, p. 258 (anatomy). — Quadrula {Rotun- 

 daria) tuberculata Simpson, '14, p. 903. 



Abundant in the larger rivers, going rather far up toward the 

 headwaters. The extreme points are: Clinch River, Clinchport, 

 Scott Co., Va. ; North Fork Holston River, Mendota, Washington 

 Co., Va. ; South Fork Holston River, Pactolus, Sullivan Co., Tenn. ; 

 Nolichucky River, Chunn's Shoals, Hamblen Co., Tenn. I have it 

 also from Boyd Creek at Boyd Creek, Sevier Co., Tenn., a very 

 small tributary of French Broad. 



In the other eastern tributaries of the Tennessee (Little River, 

 Little Tennessee, and Hiwassee) it has not been found, and also no 

 records are at hand from Powell River. 



Type locality: Ohio River. 



Genus: Plethobasus Simpson (1900). 

 Ortmann, 1912&, p. 259. 



20. Plethobasus cooperianus (Lea), 1834. 



Unio cooperianus Lea, '34. — Unio cooperianus Lewis, '71. — Unio 

 cooperianus Pilsbry & Rhoads, '96. — Plethobasus cooperianus 

 Ortmann, '126, p. 261 (anatomy). — Quadrula cooperiana Simp- 

 son, '14, p. 852. 



In the Tennessee River at and below Knoxville, down to Chatta- 

 nooga (Pilsbry & Rhoads). Also in the lower Clinch River; I have 



