MOLLUSCA. 







Patella Comprcssa. 



Patella Scutellaris. 



Patella Cymbularia. 



Patella Cochlearia. 



Of the genus Patella, or Limpet, the general characteristics are, that they have a body more or less 

 circular, conical above and flat beneath, with a large, oval foot, which is thick and overlapped, on its whole 

 circumference, by the edges of the mantle, which are fringed. The shell is oval, or circular, with a sum- 

 mit upright, or curved more or less forward. The cavity is simple, and more or less deep, and the border 

 is entire and horizontal. 



The Patella Vulgata is a species of the above, whose summit is obtuse, vertical, nearly medial, and 

 whose shape is conical. It abounds in the English Channel, and is found on the coasts of the European 

 seas generally. The varieties of this species are innumerable. 



In the Patella Deaurata the shape is somewhat Less conical than that of the above, and the summit is 

 located a little forward of the position of that, with a slight inclination in the same direction. Its resorts 

 are the Straits of Magellan, and the Falkland Isles. 



The Patella Compressa is a species, oval in form, elongated and compressed at the sides. Its locality 

 is the Indian seas. 



In the Patella Scutellaris, the summit is sub-anterior, and very little developed, and the general form is 

 perfectly flat, or depressed. 



The Patella Cochlearia is also a depressed, or flat-shaped species, whose summit is scarcely indicated at 

 all, and which are much narrower before than behind. 



The Patella Pectinata is an oval species, with a well marked summit, manifestly inclined forward, and 

 sub-marginal, and with a border slightly convex in the middle. Its locality is the Mediterranean sea. 



The Patella Cymbularia is oval-shaped, delicate, nacreous, and with a festooned border, and its summit 

 is still more distinct and marginal than that last described. 



The Limpets inhabit all regions of the globe, except the arctic regions. The Common Limpet may be 

 found on every rock, and large stone at the sea-side. The variety of the modes in which it attaches itself 

 to the rocks, is well worthy examination. All, who have seen this animal alive, know how tenaciously it 

 fixes itself to the rock. It does this by producing a vacuum between its body and such rock, the conse- 

 quence of which is, that atmosperic pressure keeps it so tightly fixed to the rock, that a ftrong knife-blade 

 is required to detach it. 



Sometimes a large shell is picked up, covered with Limpets, which adhere to it firmly, in defiance of the 

 rolling of the waves, and all the agitations to which it must be subjected. 



Patella Deaurata. 



Patella Pectinata. 



Patella Vulgata. 



2*W 

 Corcmon Limpet. 



