GASTEROPODA OF THE EOCENE MARLS. 215 



PLEUROTOMID^. 

 Genus PLEUEOTOMA Lamarck. 



Pleurotoma surculitiformis n. sp. 

 Plate XXXIII, Figs. 3, 4. 



Shell elongate and slender, spire elevated, turreted, containing five 

 or six volutions, and forming, above the point of greatest diameter of the 

 body whorl, about three-fifths of the entire length of the shell. Body 

 volution rather large in proportion to those above. Volutions concave 

 above but rapidly sloping, ventricose, and rounded below the angle, the 

 last one extended below, forming a short beak. Aperture moderately 

 large. Shell marked by fine, even, spiral lines over its entire surface; 

 also by finer transverse lines which are broadly curved backward on the 

 upper concave portion and forward on the body of the whorl. 



This species is somewhat related in its form and surface striae to 

 P. elaborata Conrad, from the Claiborne beds (Foss. shells Tert. Forma- 

 tions, p. 52, PI. XXII, Fig. 19), but differs in the smaller number and higher 

 volutions and in the somewhat longer beak. It also resembles P. alternata 

 Conrad, from the same beds figured on the same plate, in the form of the 

 volutions and surface markings but is a less robust and smaller shell and 

 the anterior beak is proportionally shorter. 



Formation and locality: In the upper layer of the Upper Grreen Marls, 

 at Shark River, New Jersey. From the collection at Rutgers College. 



Pleurotoma regularicostata, n. sp. 

 Plate XXXIII, Figs. 7-9. 



Shell small, very slender, spire elevated, forming less than half of the 

 entire length of the shell; the volutions rather high between sutures, num- 

 ber unknown. Body volution and beak forming rather more than half of 

 the entire length; moderately ventricose in the middle without perceptible 

 angle, but with a slightly concave depressed sulcus below the suture. Su- 

 tures distinct, bounded below by an elevated ridge. Anterior beak long, 

 slender, and bent. Aperture apparently of medium size. Surface of the 



