274 PROCEEDINGS OF THE ACADEMY OF [Feb., 



whorl is more prominent, flattened and divided into two coarsely 

 nodose sections by a fine stria. In pluriplicata the whorls are rela- 

 tively much more elongate, and, from the suture for about one-sixth of 

 the length, are flattened; the next sixth of the length is occupied by 

 a small concavity containing a nodulose line, which is even more prom- 

 inent than the preceding flattened collar; the surface thence to the 

 anterior limit of the whorl, occupying fully two-thirds of the length, is 

 still more elevated but flattened, cj'lindrical and divided into about 

 four nodose rings by three rather coarse equidistant revolving grooves. 

 The canal is more prolonged and more obconic than in coelata, and the 

 plications of the columella number some four to five. Length of a 

 specimen of about seven body whorls 35 mm., width 9.5 mm. Length 

 of a specimen of coelata of the same number of w^horls 21 mm., width 

 6.5 mm. Pluriplicata occurs also at Byram's Ferry. The Lower 

 Vicksburgian at A^icksljurg has not yet yielded a trace of the genus. 



Scobinella famelica n. sp. 



Very slender and elongate, the aperture narrow, scarcely at all wdder 

 than the canal, from which it is but feebly differentiated, both 

 together constituting but little more than a third of the total 

 length of the shell. The nucleus is rather small, of about three 

 whorls, with its summit obtuse. Sul^sequent whorls each with 

 a prominent double collar subjacent to the suture and a broad 

 obtuse and strongly elevated revolving keel, fully a third as wide as 

 the length of the whorl and divided into two subequal rings by a re- 

 volving groove, situated below the middle of the whorl ; this duplex 

 ring is obliquely and coarsely nodose. In the concavity between 

 the collar and the elevated keel there are two or three fine revolving 

 lines, the posterior of which is finely and more or less evenly nodulose. 

 The anterior margin is a fine line on a level with the duplex ring and 

 separated therefrom by a narrow deep concavity. Columella with six 

 or seven rather unequal, close-set oblique folds, forming a slightly 

 tumid columellar band as wide as the distance separating it from the 

 posterior angle of the aperture. Length about 25 mm., width 4.5 mm. 

 It occurs exclusively in the Upper Vicksburg marl and is rare. 



Scobinella maoer n. sp. 



Upper Vicksburg. This species resembles the preceding in general 

 form and sculpture_.but has only two folds on the columella. These 

 folds are strong, subequal and do not seem to be attended by any 

 adventitious plicae. This species is elongate and very slender, the 

 nucleus simple and of about three whorls. Each of the subsequent 



