GONIOBASIS. 269 



pressed; whorls about eight, convex and varicose; aperture rather 

 small, subrhomboidal, whitish within ; outer lip acute, slightly sin- 

 uous ; columella bent in and twisted. 



Habitat.— Tennessee; Prof. G. Ti'oost: Alabama; Prof. Tuomey. 



Diameter, -25 ; length, '5i of an inch. 



Observations. — I have only seen two specimens and indeed I have 

 some doubts if that from Alabama be not specifically distinct. That 

 from the late Prof. Troost I consider the type. It has been in my 

 possession manj' years. They are very much the same in 

 outline and size, and both have veiny lines on the body- 

 whorl. That from Alabama is, however, slightly more in- 

 flated, is of a darker color, and has plica; on the apical whorls ^* 

 with striaj beneath. It also has a less number of whorls by 

 two. When more specimens shall be found from both habitats, and 

 these differences be found to be persistent, I would consider them as 

 distinct species. The aperture is about one-half the length of the 

 shell. I name this after my young friend, Mr. W. M. Gabb, who has 

 done much to advance the couchology of our country. — Lea. 



170. G. sordida, Lka. 



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



170, t. 5, f. 15. Obs., iii, p. 8. DeKay, Moll. N. Y., p. 94. Reeve, Monog. 



Melania.. sp. 449. JAV, Cat. 4th edit., p. '275. Troost, Cat. Shells Tennessee. 



Catlow, Conch. Xomenc, p. ISS. AVheatley, Cat. Shells U. S., p. 27. Binney, 



Check List, Xo. 24G. Brot, List, p. 33. 

 Potadoma sordida. Lea, Chenu, Manuel de Conchyl., i, f. 1971. II. and A. Adam.s, 



Genera, i, \>. 299. 

 Melania perfusca. Lea, Philos. Proc, ii, p. 82, Oct., 1841. Philos. Trans., ix, p. 18. 



Obs., iv, p. 18. Wheatlev, Cat. Shells U. S. p. 2G. Jay, Cat., 4th edit., p. 274. 



BiNXEY, Check List, No. 201. Bkot, List, p. 31. Keeve, Monog. Melania, sp. 



3.54. 

 Melania incurta, Anthony, Reeve, Monog. Melania, sp. 300. Brot, List, p. 38. 

 Mehtnia plebeius, Anthony, Boi^t. Proc., iii, p. 3()2, Dec, 18.50. Reeve, Monog. 



Melania, sp. 414. Binnev, Clieck List, No. 209. 

 Melania 2)leheia. Anthonj-, Brot, List, p. 38. 

 Melania brunneu, Anthony, Ann. N. Y. Lye Nat. Hist., vi, p. 92, t. 2, f. 10, March, 



ia')4. Binney, Check List, No. 41. Bkot, List, p. 39. Reeve, Monog. Mela- 

 nia, sp. 319. 

 Melania Paula, Anthony. Brot, List, p. 40. 



Description. — Shell smooth, conical, somewhat thick, dark horn- 

 colored; sutures impressed; Avliorls somewhat convex; aperture 

 rather large, somewhat rounded, within bluish. 



Habitat. — Tennessee; Dr. Troost. 



Diameter, -40 of an inch; length, 1-02 inclies. 



