53 



lions on the inner face of the right margin. Operculum 

 with a projecting tooth, 

 *N. LITTORALIS. Turt. Lin. Pen. Brit. Zo., vol. 4, 

 pi. 87, fig. 143. Mont. Test. Brit., vol. 2, p. 467. Stew. 

 Elem., vol. 2, p. 417. Flem. Brit. An., p. 318. Abun- 

 dant. The Turbo Neritoides, as marked in the collection 

 of the Museum, from the Mediterranean, is too clearly 

 like a variety of this shell with alternate broad stripes of 

 yellow and brown in the direction of the whorls crossed 

 by zigzag markings of the same, to admit of a doubt as to 

 their identity with those found on our shores ; but in the 

 shell at least, there is not sufficient grounds for considering 

 them as forming a distinct species. 



NATICA. 



GENERIC CHARACTER: The shell suhglobular, um- 

 bilicated ; aperture entire, semicircular ; left lip oblique, 

 not toothed, callous ; the callosity modifying the umbilicus, 

 and sometimes covering it; right lip acute, always smooth 

 inside. An operculum. 



* N. GLAUCINA. Nerita G. Turt. Lin. Pen. Brit. 



Zo., vol. 4, pi. 87, fig. 141. Mont. Test. Brit., vol. 2. 

 p. 489. Slew. Elem., vol. 2, p. 417. Natica G. Flem. 

 Brit. An., p. 319. N. Monilifera. • Forbes, Fauna Mo- 

 nensis, p. 29. Common of small size ; but 1 have never 

 seen it so large any where else as at Par. 



N. ALDERI. Forbes, Fauna Monensis, p. 31. This 

 species has been lately discovered, as distinguished from 

 the last, with the young of which it has been confounded. 

 Two specimens were procured from near the Land's-end. 



N. NITIDA. Flem. Brit. An., p. 319. A single specimen 

 was obtained from near the Land's-end. For the two last 

 named species, as well as several other of the smaller 

 species of Cornish shells, I am indebted to the kindness of 

 Mr. William Curnow, Gardener, of Newlyn; who has 

 collected them with persevering industry. 



* N. PALLIDULA. Nerita P. Turt. Lin. Mont. Test. 

 Brit., vol. 2, p. 4G8. Stew, Elem., vol. 2, p. 418. Flem. 

 Brit. An., p. 320. Not common. I found a specimen at 

 Tailand sand. 



*N. LACUNA. Helix L. Mont. Test. Brit., vol. 2, 

 p. 428, pi. 13, fig. 6. Natica L. Flem. Brit. Au„ p. 320. 

 Scarcely common. 



I AN THINE A. 



The shell inflated, conoidal, thin ; aperture triangular. 

 Columella straight, projecting beyond the base of the right 

 lip ; which has a sinus in the middle. No operculum. 



