OF MOLLUSCA. 49 



cannot perceive any traces. Between the mouth and the foot, and 

 parallel to the supra-oral flap, is a larger, thin, smooth, somewhat 

 undulated flap, extending on each side nearly to the middle of the 

 foot in a semicircular manner. The mouth small, proboscidiform, 

 with a large roundish, bright red, lingual or pharyngeal mass. The 

 mantle very thin, opening very widely in front, where it forms a 

 thin, dense, yellowish flap, covering the branchial cavity, of which 

 the surface is smooth ; the branchia large. The intestine convo- 

 luted, terminating on the right side of the respiratory cavity ; the 

 liver dull olive, forming the last, very slender turns of the spire ; the 

 ovary pale yellow.— Macgilliv. Moll. Aberd. p. 346. 



Lingual membrane of Neverita castanea linear, narrow, transpa- 

 rent in front, much dilated, half-ovate, rather acute in front, truncated 

 behind. Teeth 3 • 1 • 3, transparent ; central rather broad, front 

 edge very broad, produced on each side, apex recurved, with three 

 rather large denticles, the central largest ; inner lateral broad, the 

 upper edge of the inner part recurved, entire ; outer lateral small, 

 subulate, curved, entire. 



Animal of Neverita Alderi with a produced globular pink head 

 (or proboscis ?), having the mouth, which is longitudinal and pear- 

 shaped, in front, below which is a little foot-like process ; jaws car- 

 tilaginous, square, toothed in front like a saw ; tongue like that of a 

 Littorina, but shorter and broader in proportion ; mouth pinkish- 

 white. Between the mantle and head is a sort of veil, which is 

 furnished with two distant triangular tentacula, one of which is 

 colourless, and the other pink, dark brown at the tip, but with no 

 trace of an eye. Foot pinkish- white, its sides variegated brown. — 

 Forbes, I. c. 



M. Deslongchamps describes the mantle of Neverita castanea 

 as very large, covering and entirely hiding the shell, like that of 

 Cypreea, but he observes that it is only the right side of the mantle 

 that is produced over the shell ; the head and neck are very large, 

 and when all the parts are well developed, the animal has the general 

 appearance of Bulleea aperta. — Bull. Sci. Nat. 1825, x. 296. He 

 appears to have mistaken the foot for the mantle. 



3. POLINICES. 



Shell half-ovate, solid ; spire conical ; mouth half-ovate ; inner 

 lip depressed, with a slight central cross-groove. 



1. P. mammilla, t. 50. f. 5, t. 122. f. 3. (Ruma m.), Adams, Gen. 



Moll. t. 22. f. 6. 



2. P. chrysostoma, t. 122. f. 1. 



3. P.? Uber, B'Orb. Voy. A. M. t. 55. f. 12, 13. 



4. Mammilla. 



Shell ovate; spire conical; mouth large, open; inner lip rather 

 thickened, reflexed. Operculum large, thin. 



