513 



21. Neritina aculeata (pi. ex. f. 32, 33, 3i), Omelin, 

 3686. Chemn. t. x. pi. 169. f. 1042. N. sulcata, Ni/st. 



N. testa transverse ovali, extus cpidermidc olivacea induta; 

 costis transversis moniliformibus, uonnimquam spinosis, ornata; 

 spira laterali, plana, obtecta ; apertura magna, margin! 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 septiform, purpHsh, and irregularly toothed. 



Island of Sumatra. 



22. NERiTrNA SQUAMAPiCTA (pi. cxj. f. 79), Recluz, MS., 

 Mus. Cum. 



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

 squamiformibus per fascias tres picta, epidermide tenui ohvacea 

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

 apicem undatim extenso, spiram obtegente ; columella complanata, 

 dentata. Operculo 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 line, 

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

 at the margin. The outside is marked by squamiform Hnes, 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), 8owerby, junr., 

 Pro. Zool. Soc, 1849. 



N. testa crassa, transverse ovata, extiis lineis griseis squami- 

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

 apertura ovali, sanguinea ; labio externo superne subsinuato, ad 

 apicem extenso, spiram obtegente ; columella complanata, margine 

 Isevi. 



ResembHng N. 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. 



