NITIDELLA. 113 



Section II. Nitidella, Swain?. 



Shell oval, smooth, with elevated spire ; aperture somewhat 

 effuse below; columella with two small anterior plications ; outer 

 lip somewhat thickened. 



C. L^VIGATA, Linn. PI. 46, figs. 16-21. 



Shell thin, ovate, somewhat ventricose, smooth, shining, under 

 a thin epidermis ; white, with coarse or fine longitudinal, brown 

 zigzag lines, often broken up into spots and maculations ; the 

 suture is often maculated with white, and there is frequently a 

 band of chocolate spots on the periphery, and visible on the 



spire-whorls. Length, *t-'8 inch. 



West Indies. 



There are two well-marked types of coloration in this common 

 species, with intermediate stages : in one, the shell is covered 

 by alternate irregular longitudinal markings of white and 

 chestnut, the suture is not maculated, there is no band on the 

 periphery ; in the other, the longitudinal lines are so close and 

 fine as to nearly cover the shell with a chestnut-color, and are 

 often broken up into spots and maculations ; upon this back- 

 ground are white inaculations at the suture, and a row of chocolate 

 spots on the periphery. The synonyms are C. alaperdicis, 

 Reeve (fig. 18), C. concinna, Sowb. (fig. 19), and possibly (7. 

 faleonta (fig. 20), and C. helvia (fig. 21), Duclos the two last 

 being undescribed but figured and named. 



C. LIVESCENS, Reeve. PI. 46, fig. 22. 



Shell ovately turbinated, rather solid ; spire sharp, finely 

 ribbed towards the apex ; whorls rather stout, convex, smooth ; 

 orange-brown, shining, bluish, marbled with white clots ; columella 

 lipped, aperture rather small, purplish, lip thickened, slightly 

 contracted in the middle, denticulated within. Length, '5 inch. 

 Philippines (Cuming) ; Sandwich Is. (von Martens). 



I have not seen this species, but Reeve's figure is very sug- 

 gestive of C. Isevigata. 



C. NITIDA, Lam. PI. 46, fig. 23. 



Shell narrowly oblong, compressed, smooth, shining ; irregu- 



15 



