210 INTEODUCTION TO CONCHOLOGY. 



in the vegetable kingdom present a greater variety of 

 specific form. 



Family III. Capulacea. 



Look on tlie tiny anchors, by whose aid 

 Some shell-fish moor themselves to slippery rocks, 

 Heedless of waves or winds, that madly rage 

 Ai'ound their homes : they all unmindful. 

 Dwelling in silence. 



Compensatory contrivances are frequently observable in 

 the lower orders of creation,, by means of which local 

 disadvantages are obviated. The present family, which 

 constitutes a natural and well-defined group, presents, 

 in this respect, an interesting and peculiar organiza- 

 tion, conferring the power of depositing a testaceous cup 

 or plate on the smooth and slippery sides of marine 

 rocks. 



Four genera belong to the Capulacea, in each of which 

 a striking peculiarity exists : — Crepidula, Cal^ptrcea, Kip- 

 ponyx, and Pileojms, 



The genus Crepidula comprises that portion of the 

 Capulacea in which the internal appendage assumes the 

 shape of a horizontal septum or shelf (the Shpper Limpets) . 



