206 PROCEEDINGS OF THE ACADEMY OF [1895. 



NEW SPECIES OF THE GENUS CERION. 

 BY H. A. PILSBRY AND E. G. YANATTA. 



Mr. C. J. Maynard has lately made known certain characters of 

 the internal teeth or lamella? of the species of the genus Cerion 

 found by cutting the shell open. By this means, many species con- 

 siderably alike externally are found to he well distinguished when 

 their interiors are examined. Mr. E. G. Vanatta having engaged 

 to make the necessary sections, a considerahle portion of the Cerious 

 of the Academy's collection has been thus reviewed, and various new 

 species brought to light, some of which may be briefly diagnosed 

 as folloAvs, further information and figures being reserved for a 

 future communication : — 



Cerion ( Paracerion | tridentatum Pilsbry and Yauatta. 



Shell similar externally to C. incanum, but aperture long, ovate, 

 much higher than wide ; cone of spire longer, several whorls following 

 the nepionic ones densely striate. Parietal lamina small, short, cen- 

 tral, with a smaller accessory denticle to the left of and beyond its 

 inner end, and another lamina slightly to the right and deeper 

 within. Alt. 25- 27^; diam. 9-10 mm. Cuba, R. Swift, 



The section Paracerion P. and V. is proposed for forms having 

 the tooth arrangement described above. 



Cerion (Paracerion) basistriatum P. and V. 



Shell allied to C. striatellum in form and tooth arrangement, but 

 lacking riblets on the intermediate whorls, basal whorl costulate ; 

 substance much thinner. Alt. 16*-18; diam. 8-9 mm. Cabo 

 Cruz, Cuba. 



Cerion (Maynardia) felis P. and V. 



Shell short, stout, cylindrical, with short but straight and rather 

 acute cone; strongly costate throughout (except nepionic whorls), the 

 ribs curved, 16 on penult, and on next earlier whorls, widely spaced. 

 Entire surface closely sculptured with unevenly spaced, (hep, incised 

 spiral strice. Whorls 10, slightly convex. Aperture ovate-cordate, 

 nearly as wide as high, over a third the shell's length. Lip 



