MUREX ROCK SHELL. 95 



MUREX * 



BRANCHED MUREX. 



Specific Character. Shell oval with three foli- 

 ated varices ; beak short and truncated ; the colour 

 of this shell varies greatly ; it is sometimes of an 

 uniform whiteness, sometimes pale yellow, pale 

 red, hrown, nearly black, and sometimes the 

 whorls are of one of these colours, and the folia- 

 tions of another. Its dimensions also differ 

 greatly ; varying from two to five inches, and 

 being about half as broad. 



There is a circumstance of unusual interest to 

 be observed in the manner in which this animal 

 increases the size of its shell, and which shews 

 most admirably the regularity and beauty of the 

 laws of nature, and directs the mind to the con- 

 templation of the wisdom and power of the Crea- 

 tor, who alone could teach these little animals 

 how to construct an habitation so perfectly adap- 

 ted 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 of the last volution already formed, 

 which portion is terminated in this species by a 

 foliated, in some by a spinous varix, it is obvious 

 that these foliations or spines must be in the way 

 of the future increase of the shells, unless they 



* Plate IV. fig. 1. 



