514 



24. Neritina Morio (pi. cxiv. f. 1G3), Sowerby, Pro. Zool. 

 Soc, 1832, p. 201. 



" N. testa subovali, transvcrsim striata, atra ; apertura palles- 

 cente ; columella superne emarginata, in medio denticulata. Long. 

 0° 7'; lat. 0° 75' poll. Hab. : ad Insulas Polynesias." 



Transversely oval and striated, black outside, pale fawn in the 

 aperture. The spire, consisting of two or three whorls, is flat. 

 The operculum is granulated. The teeth on the columella are 

 very obtuse. Altogether, the shell has much more the appearance 

 of a Nerita than that of a Neritina. 



On coral reefs at Ducie's and Easter Islands, South Seas. 

 Cuming. 



25. Neritina labiosa (pi. cxi. f. 80), Sowerhj, Conch. 111. 



f.48. 



N. testa, crassa, transverse subovali, extus epidermide viridi, 

 lineis et maculis nigris picta, induta ; spira depressa ; apertura 

 fusca, magna, lata, margine confluente ; columella recedente, ob- 

 lique complanata, margine dextro lsevigato. Operculo carneolo, 

 margine corneo. 



Of the same principle in make, but not of an oval form, as in 

 N. Petitii. The spire is very small, the aperture large, and its 

 margin continuous on the same plane. The external surface is 

 crossed by irregular fine striee in both directions. 



Island of Luzon, Philippines ; on stones in a rapid river. 

 Cuming. 



26. Neritina fluviatilis (pi. cxv. f. 178-186), Linn, Syst. 

 Nat, p. 1253, var. f. 80. N. intexta, Villa, f. 189. N. zebrina, 

 Recluz, Rev. Zool., 1841, p. 341. f. 178. N. Polaponensis, 

 Recluz, MS., f. 184. N. numidica, Recluz, Rev. Zool., 1841, 

 p. 346. f. 179. N. Hildreichii, Schwerzenb., f. 182. N. mittre- 

 ana, Recluz, Rev. Zool., 1842, p. 181. f. 183. N. thermalis, 

 Boubee. N. sardoa; N. trifasciata, Menlce. 



N. testa transverse elongata, laevigata, varie picta, ; spira parva, 

 vix elevata, ; apertura magna, semilunari ; labio interno laevi, sub- 

 concavo. 



Generally much lengthened in the transversely oblique directiqp, 

 with the body-whorl, and consequently the aperture, very large 

 in proportion to the spire, which is small. The columella is septi- 

 form, slightly concave and smooth at the edge. It was not until 



