206 I.AND AND FRESH-WATER SHELLS OF N. A. [pART IV. 



Mr. Say (cover of No. 6 Am. Conch,) says this equals his 

 Melania semicarinata^ but I can see no good reason to unite 

 them, as that shell has not the longitudinal folds of acuta. 

 The specimen figured by Mr. Lea, and here copied, is evi- 

 dently not mature. A shell closely allied to this species 

 inhabits the Great Lakes, etc., and IVtr. Lea and other con- 

 chologists labeled it acuta. It is never plicate and I have 

 described it under the name of Haldemani. 



89. G. subeylindracea, Lea. 



Melania subeylindracea, Lea, Philos. Proc, ii, p. 12, Feb., 1841. Philos. Trans., 

 viii.p.ltii), t. 5, f. 14. Obs., iii, p. 7. DeKay, Moll.,New York, p. 94. Troost, 

 Cat. Shells, Tenn. Binney, Check List, No. 253. Wheatley, Cat. Shells, 

 U. S., p. 27. Catlow, Conch. Nomenc, p. 1S8. Bkot, List, p. 39, Reeve, 

 INIonog. Melania, sp. 399. 



Potadoma subcijUndracea, Lea, Adams, Genera, i, p. 299. 



Description — Shell smooth, subcylindrical, somewhat thick, horn- 

 color; spire obtusely elevated; sutures impressed; whorls convex; 

 Fig. 406. Fig. 407. ^^pcrture small, ovate, whitish. 



Habitat. — Tennessee; Dr. Troost. 

 Diameter, -32 ; length, 'Sa of an inch. 

 Observations. — This is a club-shaped species with 

 an aperture about the third of the length of the shell. 

 All the specimens sent by Dr. Troost are more or 

 less decollate. — Lea. 



Figured from Mr. Lea's plate. Some specimens are more 

 lengthened and cylindrical than the tj-pe specimen. 



90. G. baeulum, Anthony. 



Melania bacuhim, Anthony, Ann., N. Y. Lye. Nat. Hist., vi, p. 08, t. 2, f. 10, March 

 1854. BiNNEY, Check List, No. 27. BKOT, List, p. 34. Reeve, Monog. Mela 

 nia, sp. 431. 



Description. — Shell conical, thick; of a dull, reddish-brown color, 

 with a lighter shade near the upper part of each whorl. Spire much 

 elevated, not diminishing rapidly as it ascends, and with nearly a rec- 

 tilinear outline; whorls eight remaining, and with an appearance 

 of having lost several by truncation ; hardly convex and with a 

 deeply impressed suture; aperture small, broadly ovate, light red 

 within; columella rounded, indented, with a small sinus. 



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