No. 30. NERITA. 



Nerite. Inhabitant a Limax*. 



Shell univalve, spiral, gibbous, flattish at bottom, aperture semiorbicular or 

 semilunar, pillar lip transversely truncated, and flattish. There is considera- 

 ble variation in the form and markings of the Neritse; some are spiral, with 

 prominent whorls; others have their whorls partly or wholly concealed; some, 

 again, are umbilicated, while others are perfectly entire and solid; and many 

 have the umbilicus partially covered by a repand lip, or fissurated nodule. 



The back of the shell is sometimes covered with strong, elevated ribs; and, 

 in a few species, with spines. It is often only minutely striated, and has fre- 

 quently a perfectly smooth surface and a brilliant polish. 



These shells inhabit the shores of the sea, rivers and lakes. Some are 

 found adhering to sea-weed, pieces of wrecks, or other extraneous substances; 

 others are only met with in deep waters, and may be taken in nets. Most of 

 the kinds are exceedingly beautiful, and the animals are often eaten by the 

 natives of the sea shores. The species are numerous. Nothing can exceed 

 the beauty and delicacy of the miniature painting with which many of the 

 Neritae are adorned ; and, viewed with a magnifying glass, the most highly 

 finished touches, upon the smallest scale, are discernible upon their enamelled 

 surfaces. The Polished Neritae are surpassed by none for beauty and variety. 

 Many are smooth shells, and display a brilliant lustre, under which are dis- 

 coverable the most superb party-colored marks, bands and dots, that can pos- 

 sibly be imagined. They are mostly clouded with green, having intermediate 

 bands of pale pink; but those are considered the rarest, and certainly the most 

 beautiful, which are of a perfect jet black, having three or four bright scarlet 

 bands, which run in a parallel direction with the convolutions of the shell. 

 Some are from India; but the most esteemed are brought from the South 

 Seas. The aperture or mouth is of a pure white, sometimes having the throat 

 of a beautifully delicate pale yellow. The N. Littoralis is often gathered in 

 England with the perriwinkle, as it frequents the same situation. It is, how- 

 ever, much smaller, and its flesh is not reckoned so good. 



