GASTEROPODA OF THE LOWER GREEN MARLS. 61 



TrACHYTRITON ? MULTIVARICOSUM, n. Sp. 



Plate V, Figs. 13, 13. 



Shell of medium size and rather ventricose, with an elevated spire, 

 which is composed of rounded and ventricose volutions, and has an apical 

 angle of about 50°; volutions four and a half or five in the cast, the 

 number not definitely known, the specimens being imperfect at the apex; 

 sutures very distinct and marked; body volution proportionally large 

 and full, especially in the upper part, and slightly extended below; the 

 beak rather long, slightly twisted, and provided with a rather large canal; 

 aperture large, elongate-elliptical, acute above and extended below, the 

 length about three times the width; columella, as shown by the cavity left 

 by its removal, rather strong and perfectly smooth; surface of the cast show- 

 ing remains of numerous closely .arranged, vertical folds marking the upper 

 portion of the volutions, but becoming indistinct on the outer half of the 

 last one; three of these on each volution slightly stronger than the others; 

 also, marked by spiral lines or ridges, which have left deep grooves on the 

 inner surface of the volutions of the cast, and also mark the outer half of 

 the body whorl, becoming quite distinct on the margin of the lip, indicat- 

 ing crenulations or denticulations on its inner surface. 



This species differs from T. Atlanticum, herein described, in its more 

 robust form, rounder volutions, and more numerous vertical folds, and the 

 anterior beak and canal seems to have been longer and more slender, and 

 also somewhat twistfed. In its general appearance it more nearly approached 

 T. vinculum Hall and Meek^ (sp-); from the western Cretaceous, but the 

 spire has been shorter, and the lower part of the body volution contracts 

 more abruptly. 



Formation and locality: In the blackish layers of the Lower Green 

 Marls at Crosswicks Creek, New Jersey. Collection at Rutgers College. 



'Hall and Meek, Mem. Am. Acad. Arts and Sci., vol. 5, n. s. 



