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THE INHABITANTS OF THE SEA. 



The Pectinibranchiata comprise all the spiral univalve shells, 

 and are by far the most numerous of all the gasteropods, as their 

 species are not counted by hundreds, but by thousands. If their 

 calcareous garment could be drawn out, it would be found to 

 consist of a tube gradually widening from the apex to the base ; 

 but what an immense variety of form and ornaments, what a 

 prodigality of splendid tints, has not Nature spread over this 

 interminable host ! The same fundamental idea appears to us 

 in thousands of modifications, one yet more elegant and capricious 

 than the other. Thus the passion of the 

 shell collector is as conceivable as that of 

 the lover of choice flowers, and when we read 

 that rich tulip-amateurs have given thousands 

 of florins for one single bulb, we cannot won- 

 der that many of the Volutes, Cones, Mitres, 

 and Harps, are worth several times their 

 weight in gold; that more than a hundred 

 pounds have been paid for a Chinese wentle- 

 trap, and that the Cyprcea aurora, which the 

 Polynesian chiefs used to wear about the neck, 

 is valued at thirty or forty guineas. 



The mode in which these beautifully painted 



structures are formed is very similar to what 



Orange Cone-sheii. takes place among bivalve shells. They are 



secreted by the glandular margin of the mantle or soft 



skin which clothes the upper part of the body of the snail, 



Mitre-Shells. 



Harp-8hell. 



and their form depends on the shape of the body they 

 are destined to cover, while the outline of the border is alike 

 regulated by that of the mantle. In the border of the mantle 



