CHAP. III. ANALOGIES OF THE MVRICIN^, Gj 



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 ]\Ielons^ or typical 

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

 a harp-shelly we cannot assimilate it to any other than a 

 coronated volute. The analogy between Cypr(Ecassis 

 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 cyprseform types. 

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

 Sti'omhidcE, 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 Cassince 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^ to the Sub-families. 



Genera of j^^;„„-^<. Sub-families of 



MuRiciN^. Analogies. Muricid^. 



Murex. Typicalofthtir respective groups. Cassincz. 



Ranella. Sub-typical. Muricin<s. 



r Spire generally longer than the"! 

 Triton. \ aperture ; base short, nearly > Buccinince. 



C truncate, straight. j 



r-., ,. „ ■ f Inner lip broad, smooth, and flat- 7 „ 



Jduhna. ^ tened ; basal channel narrow, j Purpurm<e. 



Muricidea. Base of the shell slightly produced. 'Nassimc. 



Here, again, insufficient acquaintance with the animals 

 very much lessens the interest of these comparisons : 

 and yet there can be no doubt that Murex vitiilinus of 



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