320 
THE OCEAN WORLD. 
mifera, birds, reptiles, and Mies. In the case of the superior anbn^ 8 
the hones lie in the depths of the body ; in the shelled Mollusca fb e 
1 . 47 . -i » 
bones’are placed on the superficies. It is the same system reversed- 
Other zoologists reject as altogether untenable this assimilate 
theory. “ The shell "which serves as a dwelling and a shelter cannot) 
say these authors, “ be considered as a skeleton, because it does D ° 
assume the external form of the animal ; because it does not attfl® 
itself to the organs of locomotion ; and, finally, because it is the profit 
of secretion, which increases in proportion to the development of tk 0 
body itself.” This last opinion appears to us to be the most acceptable 
However that may be, from the immense variety of form and s0 e ’ 
from the beauty and brilliancy of their colours, the shells of the TOP 
luscs are among the most attractive objects of natural history. -^° r 
is it from their beanty alone that a fine collection of shells becoM 5 
interesting: a living creature has inhabited the shell, a creature wbk'^ 
in its organization and its life, above all, by its habits, excites in a big 
degree our interest, curiosity, and admiration. It lias been said tn 
the shell “ is like a medal struck by tbe hand of Nature to commeM 
rate climates.” In short, the waters of different regions of the gl° ljL ' 
whether fresh or salt, are characterised by the presence of partied ® 
shells; moreover, the comparison of living shells with those which 1 
in a fossilized state buried in the depths of the soil, is a most import^ 
element of our knowledge touching the origin of the different beds 01 
of which our globe is constituted. 
Thus, wo must not shut our eyes to these beings, in appearance 
miserable and obscure, if we would possess a general knowledge of ‘ 1 
animal kingdom. The Creator has endowed them with many 
wod' 
derful gifts to embellish their lives, and who would dare to disreg® 1 
them ? Who could examine and compare their structure without be 
charmed with the study ? Man, who descends into the depths of 
0 
earth in search of the precious metals — who dives into the deep ^ 
pursuit of the treasures it conceals — who stoops his head over w ° r ^^ e 
ar t — would surely not refuse to bend himself for a moment to ^ 
sand of the sea, to gather in his hand, to bring nearer to his °. v 
these marvellous works of the Divine Creator ! 
The true molluscs are divisible into two great classes: 
the A ce ' 
phalous, or Headless, and those having a head of structure more or 
perfect, which are called Cephalous Molluscs. 
less 
