THE CUP-AND-SAUCER-LIMPET. 



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the shell, while in others it is a long and curiously shaped aperture, very like the 

 keyhole of a lock. The aperture increases with the shell, being hardly perceptible 

 when the animal is young, but encroaching rapidly until it removes the whole of the 

 sharp apex. These animals are mostly found at the same depth with the great tang 

 seaweeds, but are sometimes to be taken in fifty fathoms of water. The genus 

 Fissurella is a large one, comprising about one hundred and twenty species. 



THE curious DUCKBILL LIMPET inhabits the hotter seas, and is found on the shores 

 of New Zealand, the Red Sea, and the Cape. It belongs to a small genus, containing 

 about ten species. 



This shell derives its name from its peculiar shape, which certainly does bear some 

 distant resemblance to the beak of a duck. The animal is of very great comparative 

 dimensions, and while living covers the shell with its mantle. Its color is black, and 

 its sides are edged with short fringes. The eyes are set on the outer bases of the 

 tentacles. The color of the shell is very pale yellow. 



KEYHOLE LIMPET. Fissurella maxima, 



CUP-AND-SAUCER LIMPET. -Calyptrata rudla. ^Er. n ty shell below.) HUNGARIAN BONNET LIMPET. 

 LADY'S BONNET. Calyptreea equestrls. Plleopsls Uogaricus. 



DUCK-BILL LIMPET. Parmopbonis australis. Empty shell on the left. 



A NUMBER of nearly allied shells, belonging to the same family as the preceding species 

 are called CUP-AND-SAUCER LIMPETS, from the peculiar cup-shaped process on the in- 

 terior, the shell itself taking the place of the saucer. This process forms the base, to 

 which are attached the muscles which draw the animal to the rock. None of these Lim- 

 pets appear to be active, seldom quitting the spot on which they have settled them- 

 selves in their infancy. The form of the shell is extremely variable, depending greatly 

 on the substances to which it adheres, and the color seems to be quite as mutable as 

 the form. A specimen in my possession has an exceedingly thick shell, with very deep 

 ridges, and a boldly waved edge. Its color is brown, of various shades, diversified with 

 a little ochreous yellow. The " cup " is very much lighter than the interior of the shell, 

 and is of a grayish white with a slight yellow tinge, and marked with wavy streaks that give 

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