OF SANTO DOMIN^GO. 225 

 T. b i p a r t i t a . Sby., Quart. Jour., Vol. VI., p. 47. 



Distinguished by the usually finer sculpture and by the single impressed line. 



T. di si oca t a . Say., sp. 



Ceritium, Id. Say., Jour. Pliil. Acad., 1 ser.. Vol. II., p. 230. ., -'; .. 



Terebra, Id. Rve., Icou., sp. 32. ..... •■ ,:. ,■ 



T. Petitii. Kiener. 



A comniQii shell and agrees perfectly with specimens from the coast of Georgia 

 and South Carolina. 



In addition to the typical form, I have another differing from it in being very 

 much more alternate. In sculpture and other details, apart from this, it agrees 

 perfectly. ... 



OBELISCUS. Humph. .■ • 



O. c a u a 1 i c u 1 a 1 1 VI s. Gabb, u. s. 



Shell elongate, slender, many whorled, unibilicated ; spire high, whorls flat on the sides, truncated on the upper 

 mai'gin adjoining the suture, so as to produce a deep revolving channel ; at the lower angle of the whorl there is some- 

 times a corresponding channel, at other times a mei-e angle, and in still other cases only a rounded surface. When this 

 channel is present, it always, in the upjser wliorls, assists in forming the revolving groove. Under surface of body 

 whorl convex with a rib surrounding a minute umbilicus ; aperture broad, columella straight, with one transver.se 

 fold above and two, more oblique, below; the anterior of these two, borders the internal channel. Outer lip with two 

 or three transverse internal plates. Length .5 inch, width .15 inch. < ' - . 



RINGICULA. Desh. ' . .'. 



R. semi striata? d'Orb., LaSagra, pi. 21, fig. 17, 19. 



I refer my little shell to d'Orbigny's species, although it seems more elevated than 

 his figures. It has all of the details of the other characters, as well as I can make 

 them out in so minute an object. 



TURBONILLA. Risso. 



I cannot understand why Ilerrmaimsen and others place the large cretaceous Chem- 

 nitzias as congeneric with the little polished delicate forms for which Risso proposed 

 the above generic name. 



T. D o ra i n i c e n s i s. Gabb, n. s. 



Shell minute, subulate, whorls numerous, flat on the sides ; apex small, placed vertically ; surface crossed by 

 numerous fine longitudinal ribs and very minute revolving lines. Inner lip twisted, but without a distinct fold. 

 Length .28 inch. 



Distinguished from the others by its broader form and l)y the revolving sculptui-e. 

 .Nearest to " Cliemnitzia " ornata d'Oi'b., but more slender. 



T. a n g u s t a . Gabb, n. s. 



Shell small ; spire many whorled, whorls flat on the sides ; surface ornamented hy longitudinal ribs which do 

 not run over the base of the body whorl. Aperture rounded in front, inner lip simple, straight. 



About the same size as the preceding, but more slender and without any trace of 

 the revolving lines. It differs also in the mouth. 



• A. p. S. — VOL. XV. OE. 



