PLATE XLI. 



cumbered, so that the animal can move with the burden of his loaded 

 mansion without impediment. It is said that this extraneous covering 

 consists either of shell, corals, gravel, pebbles, and whatever other 

 substances happen to lie upon the ground at the bottom of the waters 

 it inhabits, and this is very probable : we have seen a shell of this 

 kind elegantly inlaid with rounded black pebbles, and thus producing 

 a contrast with the pale tints of the shell itself of very pleasing aspect. 



As we cannot conceive that a propensity so singular as these 

 animals display, not in the instance of a solitary example, but 

 throughout the whole species, can exist without some imperious or 

 impulsive cause, we are inclined to imagine that those labours of the 

 animal are intended for their own protection. Probably they may 

 be the favourite prey of some voracious fishes, and that these shells 

 are studded purposely with such extraneous bodies, either with the 

 design of adding to their strength, for the depth of the impressions 

 indicate a soft and tender texture, or that beneath this covering, as 

 in ambush, it may lie the more effectually concealed from foes. When 

 the aggregation is considerable, its own shell may be sometimes passed 

 over unobserved among the heterogeneous mass of broken shells and 

 pebbles imbedded in its shell, or agglutinated in its surface Upon 

 the whole we are induced to consider these labours of the animal as 

 intended for the preservation of the species against its enemies, and 

 one of the most singular with which the science of Natural History 

 is at this time acquainted. 



This shell, which has borne several names in the different 

 European languages, in allusion to this characteristic circumstance, 

 has been proposed by Denys de Montfort as a new genus, under the 

 name of PJiorus. The character of the Phorus genus consists in the 



