986 NERITA. 



a Variety of his Teton de Negresse, which is the Linncean 

 He/ix mammillaiis, and it may be doubted whether either 

 this or any of the sliells figured by Chemnitz from 1936 to 

 1941 ought not to be arranged with that species; but 1934 

 and 1935, which have also been quoted by GmeHn for a 

 Variety of his N. melauostoma, have more appearance of 

 belonging to N. Mammilla. 



PALLIDULA. 19. Shell smooth, sub-pellucid, with 

 a semi-lunated patulous aperture, and the 

 umbilicus large. 



Nerita palhdula. Montagu Test. p. 468. Maton and 

 Racket, in Lin. Trans, viii. p. 226. Dorset Cat. p. 51. 

 t. 20. f 4 and 5. 

 Nerita palHdulus. Da Costa Brit. Conch, p. 51. t. 4. f. 4 

 and 5. Donovan, i. t. 16. f. 1. 

 Inhabits the coasts of England. Da Costa, Bjc. 

 Shell about half an inch long, and three-eighths of an inch 

 broad, of an uniform pale brown or horn-colour, coated with 

 a darker rough epidermis, beneath which it is smooth, or 

 only very slightly wrinkled ; it has three whirls, with a flat- 

 tish spire, and the pillar-lip is thick, white and concave. 



** Imperforate, and the Pillar-lip toothless. 



CORONA. 20. Shell with a transverse row of spines 

 on the body-whirl. 



Nerita Corona. Linnmts Syst. Nat. p. 1252. Schroeter 



Fluss. p. 217, and Einl. ii. p. 283. Chemnitz, ix. part 



2. p. 68. t. 124. f. 1083 and 1084. Gmelin, p. 3675. 



Schreibers Conch, i. p. 322. 

 Clithon coronata. Leach Zool. Misc. ii. p. 122. 1. 104.? 

 Rumphius, t. 22. f. O. Petiver Amb. t. 3. f. 4. Argen- 



ville, t. 7. f- No. 2. Martini Berl. Mag. iv. t. 8. f. 30. 



Favanne, t. 6l. f. D 7. 

 y^ariety B. Smaller, and the pillar-lip minutely toothed. 

 Nerita Corona Australis. Chemnitz, xi. p. 175. t. 197. f. 



1909 and 1910. 

 Variety C. Yellowish brown, and glabrous. 

 Nerita Corona Bengalensis. Chemnitz, xi. p. 176. t. 197. f. 



1911. 

 Inhabits rivers in Asia. Linnaus. The Ganges, and China. 

 Humphreys. 



