513 



21. Neritina aculeata (pi. ex. f. 32, 33, 34), Omelin, 

 " 3686. Chemn. t. x. pi. 169. f. 1642. N. sulcata, Nyd. 



N. testa, transverse ovali, extiis epidermide olivacea induta; 

 costis transversis rnoniliformibus, nonnuiiquam spinosis, ornata; 

 spira laterali, plana, obtecta ; apertura magna, margini fulva, intus 

 coerulea ; labio externo laqueato, superne oblique extenso ; labio 

 interno subplanulato, purpureo, margine irregulariter dentato. 



Of a hemispherical shape, the external surface covered by 

 an olive-green epidermis, and having beaded ribs, upon which 

 more or less rarely there are raised, sharp spines. The apex is 

 small, lateral, and nearly hidden. The aperture is large ; the colu- 

 mella septiforra, purplish, and irregularly toothed. 



Island of Sumatra. 



22. Neritina squamapicta (pi. cxi. f. 79), Recluz, MS., 

 Mus. Cum. 



N. testa crassa, oblique, transverse ovata, extus lineis griseis 

 squamiformibus per fascias tres pictti, epidermide tenui olivacea 

 induta, ; apertura ovali, alba ; labio externo superne sinuato, ad 

 apicem undatim extenso, spiram obtegente ; columella complanata, 

 dentata. Opercido griseo radiato, ad marginem aurantio. 



More oblique and lengthened than N. Petitii, &c. The spire 

 is hidden by the outer hp, which proceeds from it in a curved hue, 

 and is sinuated at the upper part. The inner lip is flat, toothed 

 at the margin. The outside is marked by squamiform lines, shaded 

 off at the back, and strengthened in three bands. The operculum 

 is beautifully radiated with grey bands. 



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



23. Neritina sanguinea (pi. cxiv. f. 162), Sowerhy, junr., 

 Pro. Zool. Soc, 1849. 



INT. testa crassa, transverse ovata, extus lineis griseis squami- 

 formibus, per fascias tres picta, epidermide tenui olivacea induta ; 

 apertura ovali, sanguinea ; labio externo superne subsinuato, ad 

 apicem extenso, spiram obtegente ; columella complanata, margine 

 lsevi. 



Besembling JV. squamapicta, but with the upper part of the 

 outer lip less sinuated, and the edge of the columella smooth. 

 The outer lip and columella are of a reddish-brown colour. 



New Ireland ; on stones in mountain streams. Hinds. 



