510 



margine integro, ovali ; labio externo crasso, expanse ; labio in- 

 terno crasso, septiformi, margine serrato. 



Transversely oval, with the lips of the aperture confluent on 

 one plane, and the columella septiform. The lips are tliickened 

 and expanded, and in some instances include the whole shell in 

 their oval diameter. The general resemblance of this Neritina to 

 a Crepidula is remarkable. 



Ceylon ; Bengal. Yar. N. Touranensis is from Tourano. 



10. Neritina subatjeiculata (pi. cxiii. f. 138), Recluz, 

 MS. Mus. Cum. 



N. testa N. crepidularia simili, sed labii interni margine sinistro 

 in auriculam obtusam producto. 



The inner lip is produced into an auricular angle at its upper 

 junction with the outer lip. The shell, which has an ashy pur- 

 ple aperture, in other respects resembles N. crepidularia (Sp. 9). 



On the trunks of the palms growing in brackish water on the 

 Isle of Negroes. Cuming. 



11. Neritina depressa (pi. cxiii. f. 147, 148), Benson. 



N. testa N. crepidularia simiUimi, sed columella minus elevata, 

 labio externo superne subdepresso. 



The specimens are generally of a more lengthened oval than 

 those of N. crepdularia (Sp. 9), and the outline of the outer Hp 

 is more depressed at the upper part. 



Calcutta, 



12. Neritina Siquijorensis (pi. cxiii. f. 145, 146), 

 Becluz, Pro. Zool. Soc, 1843, p. 198. 



N. testa N. crepidularia simili, sed transverse magis elon- 

 gata, spira obtecta, labio externo superne depresso. 



The left margin of the inner lip is not raised, as it is generally 

 in advanced specimens of N. crepidularia (Sp. 9) ; the shell is 

 longer, and the body-whorl behind the columella more contracted 

 than in that species, to which, however, it bears a strong resem- 

 blance. 



" Island of Siquijor, in a small stream." Cuming. 



13. Neritina pulligera (pi. cxi. f. 65, 66), Linn. Syst. 

 Nat. ; Lam. Chemn. Conch, t. ix. pi. 124. f. 1078, 9. 



N. testa crassa, transverse ovata, extiis epidermide crassa nigrA, 

 induta ; spira nuUa ; apice subdepressa ; apertura magna ; labio 



