CHAP. III. ANALOGIES OF THE MURICESLE, 6? 



As no very tangible analogies exist between the shells 

 of the two first groups in each column, we may fairly 

 presume that they exist only in these hitherto not well 

 defined animals, particularly as it is only by this means 

 that the resemblance of Harpa to the Melon^, or typical 

 volutes, has been established ; and yet, when we look at 

 a harp-shell, we cannot assimilate it to any other than a 

 coronated volute. The analogy between Cyprcecassis 

 and the cowries is too strong to be insisted upon ; and 

 in this view it is quite unimportant whether the former 

 has or has not an operculum, for the relation, in either 

 case, is clearly one of analogy, and not of affinity : 

 we are disposed to consider the common C. testiculus as 

 the type, simply because it puts on more the aspect of 

 a cowry than any other species we have seen ; it is less 

 nodulous, and its slender longitudinal ribs accord more 

 with those of Oniscia and other cypraeform types. 

 Cassis, itself, is indubitably a prototype not only of the 

 Strombidtz, but of the Nassince, to which it at once 

 leads through the intervention of Cassidaria. 



(58.) It is not a little remarkable that while the 

 genera of the CassincB represent the families of the car- 

 nivorous gastropods, those of the pre-eminently typical 

 Muricince have a more especial reference to the sub- 

 families, as will be seen by the following exposition : 



Analogies of the MURICIN^E to the Sub-families. 



Genera of *, - of Sub-families of 



MURICIN*. Analogies. MURICID*. 



Murex. Typicalof thtir respective groups. Cassina. 



Ranella. Sub-typical. Muricince. 



C Spire generally longer than theo 

 Triton. < aperture; base short, nearly?- Buccininee. 



C. truncate, straight. 3 



r ... ,. ("Inner lip broad, smooth, and flat- 7 p 



Jitulma. J tened; basal channel narrow, j Purpunn*. 



Muricidea. Base of the shell slightly produced. Nassin<e. 



Here, again, insufficient acquaintance with the animals 

 very much lessens the interest of these comparisons ; 

 and yet there can be no doubt that Murex vitulinus of 

 p 2 



