ZOOLOGY. 263 



These shells inhabit the shores of the sea, rivers, and lakes, 

 some are fouiid adhering to sea-weed, pieces of wrecks, or 

 other extraneous substances, others are only met with iu 

 deep waterj^, and may be taken in nets. Most of the kinds 

 are exceodi'^gly beautiful, and the animals are often eaten by 

 the natives of the sea shores. The species are numerous, 

 though but few are common to this country, 



31. HcUiotis. Eau-Shell. Inhabitant a Limax. 



Shell e^i'-shsped, open ; spire lateral, and nearly obscure ; 

 disk longitudinally perforated with pores. Plate 5, 

 fig. 3 1 . The genus is divided into Perforated and 

 Imper J orated. 



The species are all marine, and are generally found close- 

 ly adhering to rocks or stones, within the influx of the tide, 

 and it requires some adroitness to detach them without injury 

 to their shells ; the animal is accounted delicate food. The 

 species are not numerous, and we have only one indigenous 

 to Great Britain. 



Division II. 



SHELLS, WITHOUT A RESULAR SPIRE. 



32. Patella^ Limpet. In abitant a Slug. 



Shell conical, without any defined spire. Plate 5, fig. 32. 

 The genus consists of five families : * Labiated^ or 

 furnished with au internal lip : ** Margin angular, or 

 s 4 



