UNIVALVES. NERITA. 129 



breast snail. The most usual variety of this shell is that 

 which is entirely white, having a china-ware-like appear- 

 ance ; but the rarer sorts are those which incline to a 

 brownish orange, having their lips surmounted with a 

 black margin or border. 



The Nerita stercus-muscaruni, or fly spot Nerite, is 

 beautifully dotted with brown, or rufous, on a clear white 

 ground. The Nerita fulminea, instead of being dotted, 

 is striped angularly, something in resemblance of forked 

 lightning. The Nerita rugosa is rough or wrinkled, and 

 the Nerita sulcata has its whorls obliquely plaited. 



The next species of Nerites are those which are imper- 

 forate, being at the same time toothless; among them 

 may be ranked the Nerita corona, or crowned Nerite : 

 this shell is often of a blackish color, and has its whorls 

 crowned with shorter or longer spines. The Nerita flu- 

 viatilis also belongs to this division; it is an inhabitant of 

 the rivers of Europe and Barbary, and is usually mark- 

 ed with scaly spots, sometimes rugged, streaked, or reti- 

 culate. The Nerita littoralis is found on the rocks of most 

 European shores ; and the Nerita lacustris delights in the 

 still waters and warm springs of Europe. 



Those Nerites which come next in succession, are such 

 as are imperforate, yet have their lips toothed; the prin- 

 cipal of them are the Nerita pulligera, Nerita aterrima, 

 Nerita undulata, Nerita larva, and Nerita virginea; the 

 latter of which is an inhabitant of the rivers of South 

 America and India ; it has, like many other species of 

 the Neritse, teeth on the inner lip only: its varieties are 

 infinite, and most excessively beautiful. They are, by 

 many, called the Guinea-hen or Guinea-fowl Nerites, 

 from some of the varieties resembhngthe plumage of the 



