GONIOBASIS. 179 



The figure, which is a copy of Mr. Lea's, does not repre- 

 sent the plicate upper whorls of the spire ; and Mr. Lea, it 

 will be perceived, supposed it to be a smooth species and 

 described it as such. In a number of specimens before me 

 the upper whorls are slightly ribbed. 



47. G. paucicosta, Anthony. 



Melanin paucicosta, Anthony, Proc. Acad. Nat. Sci., p. 57, February, 1860. Bin- 

 NEV, Check List, No. 198. Brot, List, p. 3(j. Reeve, Moncc- Melania, sp. 255. 



Description. — Shell conical, nearly smooth, of a dark greenish 



horn-color ; spire obtusely elevated ; whorls nearly flat, with a few 



distinct, longitudinal ribs on the upper ones ; body-whorl 



Fig. 347. 

 entirely smooth ; sutures well marked ; aperture ovate, within 



livid or purple; columella rounded; sinus small. 



Habitat. — Tennessee. 



Observations. — Belongs to a group of which jiiJews may be 

 considered the type. From that species it differs, however, 

 by its more robust form and stronger ribs. There is also a 

 marked peculiarity in this species not often observed in the 

 genus ; the spire being acute at the apex, increases regularly for the 

 first four or five turns, and then suddenly expanding, becomes as it 

 were distorted in appearance. The ribs are distant from each other 

 and very strongly expressed, differing in this respect from M. athleta, 

 which it otherwise resembles. It is a beautiful, and appears to be an 

 abundant, species. — Anthony. 



48. G. tenebrosa, Lea. 



Melanin tenebrosa, Le\, Pliilos. Proc, ii, p. 13, February, 1811. Pliilos. Trans., 

 viii. p. 170. t.o. f. 2(5. Obs., iii, p. It. DkKav, Moll. N. Y., p. 9.5. TuooST, Cat. 

 Sliells, Tenii. Wheatlev, Cat. Shells. U. S., ji. 27. Binney, Check List, No. 

 207. Cati.ow, Conch. Nonienc, p. 189. Keeve, Monog. Melania, sp. 443. 

 Brot, List, p. 39. 



Fifi 348 Fi"- 349 Description. — Shell smooth, conical, rather thick, 

 nearly ovate; spire rather elevated; sutures impressed; 

 whorls flattened; aperture rather large, elliptical, at 

 the base angular, within bluish. 

 JIaJjitat. — Tennessee. 

 Diameter, -30; length, -72 of an inch. 

 Observations. — Two specimens of this species were sent to me by 

 Dr. Troost, both of which are decollated. On one there is a slight 



