556 ORTMANN— NAYADES OF 



Everywhere in the larger rivers : Tennessee, Holston, French 

 Broad, CHnch, and Powell ; goes up, in the Powell, to Jonesville, 

 Lee Co., Va. ; in the Clinch, to Clinchport, Scott Co., Va. ;, in the 

 Holston to the South Fork at Pactolus, Sullivan Co., Tenn. ; in the 

 French Broad, it goes to the Nolichucky at its mouth ( Chunn's 

 Shoals, Hamblen Co., Tenn.). It is also in Emory River, up to 

 Harriman Junction, Roan Co., Tenn., and in Hiwassee River, at 

 Kincannon Ferry, Meigs Co., Tenn. In the Tennessee below Knox- 

 ville, and down to Chattanooga, it is extremely abundant. 



Type locality: Ohio River. 



34. Elliptic dilatatus (Rafinesque), 1820. 



Unto dilatatus Rafinesque, '20. — Unio gibbosus Lewis, '71. — Unio 

 gibbosus Pilsbry & Rhoads, '96. — Elliptio gibbosus Ortmann, 

 '12b, p. 271 (anatomy). — Elliptio dilatatus Ortmann, 'i2,b, p. 311. 

 — Elliptio gibbosus Goodrich, '13, p. 94. — Unio gibbosus Simpson, 

 '14, p. 597. — Unio dilatatus Vanatta, '15, p. 555. — Elliptio dilatata 

 Utterback, '16, p. 90. 



Common, in large rivers as well as in small creeks, possibly the 

 most widely distributed species in the upper Tennessee region, so 

 that it is heardly required to name special localities. However, it 

 should be mentioned that it is one of the species which go up, in 

 French Broad River, to Asheville, Buncombe Co., N. Car. (Walker 

 coll.). 



In our region, this species is of moderate size, and purple color 

 of the nacre prevails ; only specimens from the French Broad are 

 more frequently white-nacred. 



Type locality: Ohio River (the type is from Kentucky River, ac- 

 cording to Vanatta). 



Genus: Lastena Rafinesque (1820). 

 Ortmann, '12b, p. 297, and '15, p. 106. 



35. Lastena lata (Rafinesque), 1820. 



Anodonta lata Rafinesque, '20. — Margaritana dehisccns Lewis, '71. — • 

 Lastena lata Goodrich, '13, p. 94. — Lastena lata Ortmann, '15, p. 

 106 (anatomy). — Lastena lata \'anatta, '15. p. 554. 



