OP CONCHOLOGY. 79 



Habitation. The Murices are only 

 found to inhabit the ocean. They in 

 general are to be found on rocky 

 shores, and some of them burrow in 

 the sand. 



The shells of this genus are in 

 general thick, strong, and heavy, and 

 often rugged ; from which they have 

 obtained the name of rocks in England. 



The modern French and German 

 Testaceologists, have divided the Lin- 

 nean Murex into three genera : Fas- 

 ciolaria, Pleurotoma, and Murex. 



The first of these are shells of a fu- 

 siform or spindle shape, and smooth, 

 with several oblique folds in the pillar. 

 The Plurotoma are also spindle-shaped, 

 with the aperture terminating in along 

 canal, lip cleft near the summit. The 

 Murex are those shells of an oval or 

 oblong form, with a canal at the base, 

 and the shell externally beset with 

 prominent, longitudinal ridges, and 

 often tuberculated. 



