576 ORTMANN— NAYADES OF 



has it from Tennessee River, Little River Shoals, Knox Co., Tenn. 

 I found it chiefly toward the headwaters, in Powell, Clinch, and Hol- 

 ston. In the Powell, it goes up to Combs, Claiborne Co., Tenn. ; in 

 the Clinch, to Cleveland, Russell Co., Va. ; in the North Fork Hol- 

 ston, to Hilton, Scott Co., Va. ; in the South Fork, to Pactolus, Sul- 

 livan Co., Tenn. It seems to be alDsent from the eastern tributaries 

 of the system. 



Type locality: Ohio River. 



65. EuRYNiA (Micromya) trabalis (Conrad), 1834. • 



Unio trabalis Conrad, '34. — Eurynia (Micromya) trabalis Ortmann, 



Extremely rare. I found a single specimen in Clinch River, at 

 Speer's Ferry, Scott Co., Va. ; another one in South Chickamauga 

 Creek, Ringgold, Catoosa Co., Ga. ; and three specimens in Hiwassee 

 River, at Austral, Polk Co., Tenn. At the first locality, it was asso- 

 ciated with the next species. 



The only difference of E. trabalis and pcrpiirpurca is, that the 

 former has white, the latter purple nacre. The specimens from the 

 Hiwassee are exceptionally large, and do not taper so much behind 

 as usual. 



This species seems to have its metropolis in the Cumberland 

 system (Wilson & Clark, '14). Call cites it from Clinch and Powell 

 Rivers in Tennessee, but Lewis does not mention it from the " Hol- 

 ston" (=^ Tennessee), and I have never seen a trace of it in the 

 whole Holston drainage. According to Hinkley, it is rare in the 

 mussel shoals of the Tennessee in Alabama; the Carnegie Aluseum 

 has one specimen from Paint Rock River, at Paint Rock, Jackson 

 Co., Ala. It may be that my localities in Chickamauga Creek and 

 Hiwassee River are connected with the range in northern Alabama. 



Type locality: ? 



66. Eurynia (Micromya) perpurpurea (Lea), 1861. 



Unio perpiirpiu-ca Lea, '61. — Eurynia perpurpurea Ortmann, '13^, 

 p. 311. — Eurynia purpurpurea Goodrich, '13, p. 94. — Lampsilis 

 perpurpurea Simpson, '14, p. 133. — Eurynia (Micromya) per- 

 purpurea Ortmann, '15, p. 63 (anatomy). 



'12b, p. 340 (anatomy). — Lampsilis trabalis Simpson, '14, p. 132. 



