122 SHELLS AND SHELL-FISH. PART I. 



fifth, which so singularly represents Voluta angulata 

 and Cymbiola JSraziliensis (no less than the Pyrula), is 

 seen in F. cithera*, this latter being the second type of 

 the genus. 



(110.) That there exists mutual resemblances be- 

 tween these presumed types, and those of the three 

 preceding genera, will be evident from the following 

 comparison : 



Analogies of the Genus VOLUTILITHES. 



r Wh " y } Vexillum. VOLUTA. 

 Crenulata. Shell entirely muricated. Hebr&a. CYMBIUM. 



f Spire much lengthened; 



(. enlarged. $ 



Cithera. Ventricose ; spire very short. Bullata. VOLUTILITHES. 



1 Analogous to theStrombidce;~\ 



base, and often detached^ ?mrt ^ a ' CAPHELLA. 

 above. 3 



Perhaps it may eventually turn out that the V. musi- 

 calis || a species we do not possess in perfection is 

 one of the typical forms, and that spinosa is the other : 

 but the very singular-grooved suture of costaria and 

 bicorona appears to indicate that a peculiarity of structure 

 existed in the animal, of more importance than the mere 

 form of the shell. The analogy, or rather the affinity, 

 between costaria and the Harpulce must be apparent to 

 every one, no less than that between Voluta angulata, 

 Cymbiola Braziliensis, and Volutilithes cithera. Of 



* Ency. Meth. pi. 384. fig. 1. 



f It is not a little remarkable, that, in well-preserved specimens of the 

 fossil species from France, the body-whorl is marked by transverse orange 

 lines, completely analogous to H. vexillum. 



j If, as may be suspected, the Voluta labrella (Ency. Meth. pi. 384. fig. 3.) 

 is the true type of this division, then its analogy to the smooth melons 

 would be perfect, inasmuch as this fossil is entirely without the muricated 

 spines of spinosa : I do not, however, feel at all satisfied that I have cor- 

 rectly indicated this and the next type. 



\ As in the two species here compared. 



|| Ency. Mth. pi. 392. fig. 4. 



