UPPER TENNESSEE DRAINAGE. 591 



known from the Tennessee in North Alabama, but which has not 

 yet been recorded from the upper Tennessee. T. turgidula agrees 

 with the latter in the biangulate posterior ridge, but the biangulation 

 is much less pronounced, and the depression or -furrow in front of 

 it is less developed. In the female (deviatus), the biangulation is 

 also present, but indistinct, and the furrow is obliterated, being 

 filled by the expansion of the shell. The female resembles, to a 

 degree, that of T. florenfina, but has the shell, as Simpson states, 

 more elongated, and has fuller and higher beaks (the latter charac- 

 ters hold also good for the male). 



This species has been recorded from Cumberland and Tennessee 

 rivers (not recently found by Wilson & Clark, '14, in Cumberland), 

 and from Duck River, Tenn. (Call), but only one definite locality 

 is known (Florence, Lauderdale Co., Ala.). Hinkley reports it from 

 Shoals Creek, Lauderdale Co., Ala. The Carnegie Museum has it 

 from Bear Creek, in Franklin Co., Ala. I have found it in the 

 upper Tennessee drainage, where it is not rare in the Holston proper 

 from Knox Co. up to Austin Mill, Hawkins Co., Tenn. I found it 

 also in Emory River, Harriman, Roane Co., Tenn. Li the Walker 

 coll. it is represented from the Holston, Rogersville, which is prac- 

 tically the same locality as Austin Mill. 



Type locality: Cumberland River and Florence, Ala. 



86. Truncilla florentina (Lea), 1857. 



Unio flofentiinis Lea, '57. — Truncilla florentina Simpson, '14, p. 30 

 (excl. titrgididiis) . 



This species has not a biangulate posterior ridge, but this ridge 

 is rounded, and the radial depression in front of it is hardly de- 

 veloped, indicated only by a flattening of the shell. In the female, 

 the posterior expansion of the shell may become very large, and is 

 generally of the color of the rest of the shell, or lighter, but not uni- 

 formly dark green, as in T. capscrformis. By the latter character, 

 by the more strongly developed and more numerous denticulations 

 of the margin of the expansion, and by the greater convexity of the 

 shell, T. florentina is distinguished from capscrformis. The male of 

 T. florentina is shorter, higher, and more swollen than that of T. 

 capsceforniis. 



