LIMPETS. 227 



to the manner in which marine rocks are frequently covered 

 with their small conic habitations, is a point of little con- 

 sequence. 



The Latins distinguish them by the appropriate title of 

 Patella, the name of a small deep dish used for sacrificial 

 purposes ; and hence among early naturalists the names of 

 Patella and Learns were regarded as synonyms. Linn[eus, 

 also, preferred to adopt the genus PateUics wherein to in- 

 clude all mollusks having a dish-shaped shell ; but as con- 

 siderable differences in their habits and organization have 

 become known, it has been divided into various genera. 



The shell may be described as being elliptic, univalve, 

 not spiral, basin- or dish-shaped, or like a shield or de- 

 pressed cone, uniformly concave beneath, and having the 

 basal margin often crenated all round : the vertex or sum- 

 mit of the shell is mostly situated near the centre, and 

 always recurved anteriorly, that is, towards the head of the 

 animal. The muscular impression in the interior is elliptic, 

 and interrupted in the same direction. 



Limpets are frequently associated with the beauty or mag- 

 nificence of ocean scenery. At one time their conically-shaped 

 dwellings are seen peeping from among mimic groves or 

 gardens formed of crimson, green, or brown-coloured sea- 



q2 



