158 Bulletin American Museum of Natural History [Vol. LIIT 
This genus is estuarine and fluviatile and found throughout the 
tropics of the world. 
Baker’s recent arrangement of ae Neritine into subgenera and 
sections is almost entirely based upon characters taken from the radula. 
Since only a few of the African species have been examined in this respect, 
it is not possible to arrange them all according to Baker’s system. The 
following is a list of the species which have been reported from the Ethi- 
opian Region. 
Neritina adansoniana (Récluz). See p. 161. 
Neritina arctilineata ‘“‘Récluz’’ SowERBy, 1849, ‘Thesaurus Conchol.,’ I, p. 531, 
Pl. cxvi, figs. 223 and 224=Neritina africana ‘“Parreyss’’ RuEve, 1856, ‘Conchol. 
Iconica,’ 1X, Neritina, Pl. xxx, figs. 138a-b. Neritina nilotica Runve, 1856, op. cit., 
Pl. xxxtv, fig. 157. Neritina dongolensis “Ehrenberg” E. v. Martens, 1865, Mala- 
koz. Blatter, X11, p. 206 (as a synonym of N. africana). Nile River (originally de- 
scribed from an unknown locality). 
Neritina atra Gray, 1831, ‘Zoolog. Miscellany,’ p. 11. Fernando Po. 
Neritina crepidularia Lamarck, 1822, ‘Hist. Nat. Anim. sans Vertébres,’ VI, 
2, p. 186. This is an East Indian species which has been recorded by Krauss (1848, 
‘Siidafrik. Mollusk.,’ p. 88) from Natal; but its occurrence there is doubtful. 
Neritina cristata MorEteEt, 1864, Journ. de Conchyl., XII, p. 288. Como River, 
Gaboon. Appears to be very close to N. oweniana (Wood). 
Neritina frasert Reeve, 1855, ‘Conchol. Iconica,’ IX, Neritina, Pl. xxv, figs. 
113a-b. West Africa. Closely related to N. afra Sowerby. 
Neritina glabrata Sowerby. See p. 159. 
Neritina knorri (Récluz) SowEerBy, 1849, ‘Thesaurus Conchol.,’ II, p. 511, PI. 
cx1, fig. 78 and Pl. cxiu, fig. 150=Nerita knorri R&ciuz, 1841, Rev. Zoolog. Soc. 
Cuviér., p. 274. Neritina beckii Sowerby, 1849, ‘Thesaurus Conchol.,’ II, p. 512, 
Pl. crx, fig. 18 (not of Récluz). Neritina (Neritxa) cryptospira E. v. MARTENS, 
1879, in Martini and Chemnitz, ‘Syst. Conch. Cab., II, 10, Nerdtina,’ p. 61, PI. 
vitl, figs. 10-12. Originally described from Madagascar; this species is also known 
from the East Indies, Zanzibar, and Lourenzo Marques. 
Neritina natalensis ReEvE, 1855, ‘Conchol. Iconica,’ IX, Neritina, Pl. xv1, 
figs. 75a-b = Neritina zebra Krauss, 1848, ‘Stiidafrik. Mollusk.,’ p. 88 (not of Lamarck). 
Coast of Natal and as far north as the Pangani River. 
Neritina oweniana (Wood). See p. 162. 
Neritina rubricata Mornin, 1858, ‘Séries Conchyl.,’ I, p. 30, Pl. 1, fig. 2= 
Neritina gouldi E. v. Marrens, 1879, in Martini and Chemnitz, ‘Syst. Conch. Cab., 
II, 10, Neritina,’ p. 81, and Neritina calabarica ‘‘Mousson’”’ E. v. Martens, 1879, 
op. cit., p. 81 (as synonyms of N. rubricata). Senegambia and Assinie. 
Neritina souwverbiana Montrouzimr, 1863, Journ. de Conchyl., XI, pp. 75 and 
175, Pl. v, fig. 5 = Neritina (Vitta) pulcherrima ANGas, 1871, Proc. Zool. Soc. London, 
pp. 19 and 96, Pl.1, fig. 25. This species of New Caledonia and the coast of Australia 
has been found on the coast of Natal. 
Three species of Neritina occur at. the mouth and in the estuary of 
the Congo River. They may be separated by shell characters as follows: 
