529 



rato ; apertura extus subrotundata, intus albo-cinerascente ; labio 

 semilunari, piano, superne calloso, margiue iu medio tenuiter 

 arcuato et crenulato ; dente cardinali majore, truncate" 



M. Recluz, in describing this species, expresses a probability of 

 its being a variety of his N. bicolor ; if, however, our specimen is 

 characteristic, it is much more quadrate than that species, having 

 more of an angle at the upper part of the whorl ; and there is a 

 difference in the upper part of the outer hp, which, in N. bicolor, 

 is more curved towards the suture. 



" Sinait, province of North Ilocos, Island of Luzon ; in a small 

 mountain stream." Cuming. 



74. Neritina olivacea (pi. cxv. f. 207, 208), Guil., Rev. 

 Zool., 1841, p. 344. N. solida, Recluz, ? 



N. testa N. suhpunctata simili, sed oblique magis elongata, 

 columella, planiuscula, apertura subquadrata, epidermide olivacea 

 vel nigra. 



More lengthened in an oblique direction, and more quadrate, 

 than N. subjmnctata, with the columellar callosity near the suture 

 scarcely prominent. The colour is even, of an olive-green, or, as 

 in the variety named N. solidum, nearly black. 



Island of Luzon ; on stones in a rapid river. Cuming. 



75. Neritina chlorostoma (pi. cxv. f. 216), Broderip, 

 Pro. Zool. Soc, 1832, p. 201. 



"N. testa, suborbiculari, elliptica, olivaceo-fusca, nigro reticu- 

 lata, subfascial; apertura intus flava; labii columellaris margine 

 obtuse unidentata, rugulosa." 



Nearly orbicular, with the whorls slightly angulated, purplish 

 or greyish, obscurely banded and reticulated with black ; aperture 

 yellow, with the outer hp obtusely angulated above ; the columella 

 narrow, slightly tumid near the juncture of the outer hp, with the 

 margin crenulated, and one rather large blunt tooth near the centre. 



Tahiti ; at the mouth of a small stream, at times covered with 

 salt water. Cuming. 



76. Neritina Michaudii (pi. cxii. f. 108, 109, and pi. cxv. 

 f. 217, 218 *), Recluz, Rev. Zool., 1841, p. 315. 



" N. testa subglobosa, tenui, olivaceo-fuscescente, lineolis nigres- 



* Repeated in consequence of an oversight. 



