XIV INTRODUCTION. 



Who that breathes, and is endued with the powers 



that so widely separate man from the brute, can for one 



instant withhold his acknowledgment of an omnipresent 



Being, which is sensibly spread 



" o'er all that glides 



Beneath the wave, yea, in the wave itself, 

 And mighty depth of waters " ? 



I will now resume the special purpose of this work, 

 commencing with the Brachiopoda, as having the lowest 

 organization, and advancing upwards to the higher or 

 more perfect Mollusca. The descriptions of the ani- 

 mals or soft parts will, I regret to say, be sometimes 

 scanty and occasionally wanting. They are principally 

 taken from the observations of the late Mr. Clark and 

 Professor Forbes, Mr. Alder, and myself. My deficien- 

 cies in this respect will, I trust, stimulate other natu- 

 ralists to supply the desired information ; and I would 

 especially invite the assistance of those who have an 

 aquarium, and opportunities of keeping it supplied from 

 the various parts of our extensive seaboard. Every fact, 

 however trivial, is worth recording, because (even if it 

 is not new) it may be useful for the sake of confirming 

 the accounts given by other naturalists. Most of the 

 illustrations of molluscous animals in this volume have 

 been copied from the plates in Forbes and Hanley's 

 work, or engraved from original drawings by Mr. Alder. 

 For the figures of Crania, Crenella, and Cyamium I 

 am indebted to Dr. Saxby, and for that of Pinna to 

 Mr. Spence Bate. 



The 1st Class, or Conchifera, has been described in 

 the first volume, so far as it relates to the freshwater 

 Mollusca ; and the only other division of the Acephala 

 is the Brachiopoda, which will now be noticed. 



