NERITA. 987 



Shell half, or sometimes three-quarters of an inch long, and 

 about two-thirds as broad, with a row of long spines on the 

 shoulder of the body-whirl, and generally coated with a black 

 epidermis ; Dr. Leach thinks his Clithon coronata is a dis- 

 tinct species, but has not stated in what the difference con- 

 sists. 



RADULA. 21. Shell with transverse equally tuber- 

 culated ribs, and the aperture roundish. 



Nerita Radula. Linnaus Syst. Nat. p. 1252. Born Mus, 



p. 400. 1. 17. f. 7 and 8. Chemnitz, v. p. 289- t. igo. f. 



1946 and 1947. Schroeter Einl. ii. p. 284. Cmelin, 



p. 3676. Schreibers Conch, i. p. 323. 

 La Pelote de Neige. Favantie, ii. p. 250. t. 11. f. N. 

 Rumphius, t. 22. f. M. Petiver Amh. t. 11. f. 8. Sebuy 



iii. t. 41. f. 18 and 19- Gete, t. 23. f. 241. 

 Inhabits the coast of Amboyna. Rumphius. Bantam and 



Java. Favanne. Tranquebar. Chemnitz. 

 Shell about an inch or an inch and a quarter long, and nearly ' 

 equally broad, thin, pellucid, and of a white or greyish or 

 brownish white colour; it has four whirls, with the spire 

 somewhat produced and pointed, and the interstices of the 

 tuberculated ribs are striated. 



MAGDALENiE. 22. Shell broadly ribbed transverse- 

 ly, and black, with the inside white, and the 

 pillar yellowish ; operculum smooth and two- 

 toothed. 



Nerita Magdalenae. Gmelin, p. 3677. 

 Nerita, No. 225. Schroeter Ei?iL ii. p. 370. 

 Le Kiset, Adanson Senegal, p. 192. 1. 13. f. 5. Favanne, 

 ii. p. 206. 



Inhabits the coasts of the Magdalen Islands. Adanson. 



Adanson has described this shell to be half an inch long, with 

 three whirls, and the summit much depressed ; the body- 

 whirl has twenty broad flattish ribs, and the operculum two 

 broad approximated teeth ; Favanne considered it to be a 

 Variety of N. grossa ; but this is impossible, for Adanson 

 says that both the lips are toothless. 



CORNEA. 23. Shell roundish, obsoletely striated, 

 and the aperture toothless. 



Nerita cornea. Linnaits Syst. Nat. p. 1253. Forskael 



