CHITONID^E. 



CHITONIDJE. 



Before I enter on this family, I beg to state, that a more 

 extended experience of the Mollusca has compelled me to 

 relieve myself, in part, of the assistance of conchological attri- 

 butes, as I have found them singularly defective and fallacious 

 in reference to the existing constitutions of divisions, families 

 and genera. I therefore, as regards the past, and henceforth, 

 shall only consider the shell-coverings of the Mollusca as good 

 and useful aids, in strict subservience to the malacology of the 

 animal, and as consequential specialties emanating from the 

 vital organs ; and that the meaning of whatever appellation 

 may be attached to a division, family or genus, has with me 

 no reference to the testaceology : for instance, speaking of the 

 Muricidce, or its synonym, the Canalifera, the shell is not in 

 question, except as a corroborating incident, but the animalia 

 canalifera, whose mantles form canals; and in like manner, 

 in mentioning the Holostomata, the entire periphery of the 

 aperture is not primarily intended, but, that the mantle lining 

 it is entire. 



The use of the word ' shell/ instead of ' animal/ in the con- 

 struction of the subordinate divisions of a class, has doubtless 

 arisen from the ignorance of naturalists of the inhabitants ; 

 but as this cause is in a great measure removed, it is time 

 to abandon a system founded on fallacious bases, and have 

 recourse to nature's imperishable land-marks. 



In these observations, I do not mean to say that conchology 

 is without its use : to palaeontologists, collections of shells are 

 the only resources to denote that their fossils present similari- 

 ties to many existing forms ; but how infinitely more valuable 

 is an account of an existing animal, to inform them of the real 

 character of the relics of former epochs ! Beyond the re- 

 stricted points, conchology is totally unworthy to be the suc- 

 cedaneum of the attributes of nature, and the true worshipers 

 of the great book will rejoice at the decadence of a usurpation 

 to its just limits. 



