Description of some New Species of Fossil /Shells. 97 



Remarks. — There are three striae and a carina on each whorl, 

 but as I have but a single specimen, I cannot determine whether 

 this is a constant character. The striae are very small, and are 

 arranged, one near each suture and one on the under side of the 

 carina, near its vertex. The whorls, from the magnitude of the 

 carina, resemble a double cone, truncated at both ends. My spe- 

 cimen is fractured at the apex, so that the length and number of 

 whorls cannot be satisfactorily determined. 



T. 7nonilifera. PI. 1, iig. 11. 



T. testa turrita, tenui, transverse striata, striis muricatis vel mo- 



niliferis ; spira acuta ; anfractibus , sub-planulatis ; suturis 



impressis ; apertura sub-quadrilaterali. 



Shell turrited, thin, transversely striate, with muricate or moni- 



liferous striae ; spire acute ; whorls , somewhat flat ; sutures 



impressed ; mouth sub-quadrilateral. 



Length . Breadth -25 of an inch. 



Remarks. — This shell has four strias, three large and one small 

 one, which is near the upper suture. The sutures are very small 

 from the flatness of the whorls. It bears a slight resemblance to 

 some specimens of T, lineata^ Lea, but may easily be distin- 

 guished from that species by the striae being moniliferous, and 

 the less convexity of the whorls, &c. 



T. gracilis. PI. I, fig. 12. 



T. testa turrita, tenui, transverse striata, striis latis ; spira at- 



tenuata, acuta ; anfractibus , sub-concavis ; suturis impressis ; 



apertura sub-quadrilaterali. 



Shell turrited, thin, transversely striate, with broad striae ; spire 

 attenuated, acute ; whorls , somewhat concave ; sutures im- 

 pressed ; mouth sub-quadrilateral. 



Length — — . Breadth -1 of an inch. 



Remarks. — In this shell there are two broad striae, or rather 

 elevations, which make the whorls convex. They are placed, 

 one in the middle and the other in the upper part of the whorl. 

 The sutures are distinct. This species seems to be very fragile, 

 for although I have seen a number of specimens, none of them 

 are perfect, most of them having the apex, and all the base, frac- 

 tured. 



Vol. XL, No. 1.— Oct.-Dec. 1840. 13 



