MUREX. 



though this is commonly cleaned off before these shells 

 come into the market. 



Of Fossil species there are also many generally be- 

 longing to the tertiary beds. 



There is a circumstance of unusual interest to be 

 observed in the manner in which the animal increases the 

 size of its shell, and which shows most admirably the 

 regularity and beauty of the laws of Nature, and directs 

 the mind to the contemplation of the wisdom and power 

 of the CREATOR, who alone could teach these little ani- 

 mals how to construct an habitation so perfectly adapted 

 to their circumstances and situation : It will be observed 

 that each periodical increase of these shells consists of a 

 piece which surrounds about a third part or less of the 

 lower portion of the last volution already formed, which 

 portion is always terminated by a varix, which is more or 

 less muricated and even spinose ; it it obvious that these 

 murications or spines must be in the way of the future 

 increase of the shells, unless they could be removed from 

 that part which it is intended to cover, the animal there- 

 fore is furnished with the means, probably by a solvent 

 liquor, of eating away the lower part of these spines, so 

 that they become detached and fall off by the time that 

 he is ready to form his new inner lip upon the space which 

 they occupy, thus forming a comparatively smooth and 

 even surface on which it is to spread the testaceous matter 

 of which the addition to his building is composed. 



In our plates we have given figures of some of the 

 species which show the greatest diversity of character. 



Fig. 1 Murex Haustelliim. 



2 tenuispinosus. 



3 Scorpio. 



4 cervicornis. 



5 phyllopterus. 



6 ■ melanamathos. 



