Zoological Society. 281 



The flat and greatly eroded summit does not allow the form and 

 length of the shell to be ascertained with exactitude. It appears to 

 me to have at most a whorl and a half faintly depressed below the 

 suture. 



Operculum very like that of N. hicolor, but of a yellowish white 

 colour externally. On the inferior surface I observe that the upper 

 tooth is stronger ; the lower one annulated transversely, in a more 

 distinct manner. The intermediary plate is more compressed and 

 less sinuous at the margin, and the notch at the posterior part ap- 

 pears to me to be deeper. 



14. Nerita angulosa. N. testd ventricoso-glohosd, supern^ de^ 

 presso-pland, suhtks angulosd, olivaced, maculis luteis parvulis oh^ 

 soletis notatd ; anfractihus duohus incequaliter rugatis ; supremo 

 derosO'Concavo, aperturd suhrotundatd, antice et postice angustatd, 

 superne et inferne dilatatd ; columelld angustd, medio concavd, su^ 

 pern^ callosd, antice tenue denticulatd, medio emarginatd. 



Long. 0-72 ; lat. 0*92 ; conv. 0'60 poll. 



Hab. Casan, province of Misamis, island of Mindanao : on stones 

 in a small stream. 



Operculum oval, waved with grey on the anterior side, with a 

 narrow circular furrow ending in a strong posterior notch : this fur- 

 row bounds a superior, obtuse and circular angle. The summit of 

 an orange colour ; internal surface bearing a curved rib in the centre, 

 of greater or less width. Superior tooth yellowish and obtuse ; the 

 inferior yellowish white and substriated lengthwise ; the intermediary 

 plate between the two teeth of a citron colour, cut obliquely at the 

 margin. The depression existing at the base of the lower tooth is 

 of a flesh- colour approaching to cinnamon. 



15. Nerita circumvoluta. N. testd glohoso-suhovatd, diluthfulvd 

 in rosea vertente, punctis luteolis antice lineis nigris marginatis 

 marmoratd, zonis nigris remotis circumcinctd ; anfractihus duohus 

 nigro-marginatis ; supremo ohtuso, decorticate; aperturd alhidd; 

 lahio piano, superne calloso, antice ruguloso, et in medio arcuatim 

 emarginato. 



Long. 0-72 ; lat. 0-84 ; conv. 0*68 poll. 



Hab. ad Insulas Philippinas. 



Operculum of a Clithon, oval, of a rosy white, with a broad, rather 

 concave and central furrow ; on the interior face of a pale yellowish 

 colour, shaded with rose. One lamellated and pointed tooth near 

 the summit, and an inferior one, which is circular, subcanaliculated 

 in the centre, and striated transversely. 



16. Nerita squarrosa. N. testd ventricoso-glohosd, interdum 

 subovatd, supern^ depressd et subangulatd, epidermide squarrosd, 

 maculis rufescentibus angulatis confertis nigro seu olivaceo mar- 

 ginatis pictd, apice rotundatd, aperturd extus suhquadratd, inths 

 albido-caerulescente ; lahio suprci lutescente, piano, antice ruguloso, 

 medio arcuato. 



Var. /3. T. suhruhicundd, nigro -fasciatd, 



Var. y. l.\ roseo-purpurascente, alho-maculatd, lahio margine detriio, 

 Ann. ^ Mag, N, Hist, Vol, xii, V 



