12() UNIVALVES. PATELLA. 



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ri. WITHOUT A REGULAR SPIRE. 



PATELLA. — Limpet or Dish-Shell. 



Animal — a Limax: Shell univalve, subconic, shaped like 

 a bason, ivithont a spire. 



'J'liis numerous goiius contains two hundred and forty 

 species. They are very similar in form, which, with a few 

 exceptions, approximates to that of a cone, with its apex a 

 httle blunted. But with regard to the colors and work- 

 ings, they differ exceedingly ; some being perfectly smooth, 

 whilst others are strongly granulated and spinous; and 

 many are deeply striated or covered with elevated tuber- 

 culated rays. 



The species of the first division are entire; and are 

 furnished with an internal lip, which is strikingly observ- 

 able in the P. equestris, P, Sinensis, and P. neritoidea; 

 some of them are rough and scaly, whilst others are per- 

 fectly smooth and polished; they are known by the name 

 of Cup-and-saucer Limpets. 



Some species of this division are chambered or vault- 

 ed, and have the appearance of a slipper; such are the 

 P. porcellana, P, fornicata, and P. aculeata. 



