CHAP. IV. TYPES OF THE GENUS VOLUTA. 105 



exception to this form in the true volutes, which is seen 

 in Voluta angulata, where the spire is absolutely pointed: 

 this exception, however, is a necessary one, for other- 

 wise there would be no species which would represent 

 Volutilithes. The exterior of all these shells, so far as 

 we yet know, is covered with a thin epidermis, except, 

 perhaps, P. prohoscidalis ; so that, notwithstanding the 

 enormous foot of the animal, it does not appear that any 

 part of the shell is covered by that member. The chief 

 variations among those shells are as follows: — First, the 

 melons, whether smooth or coronated. Secondly, the 

 horned volutes, where the form is less ventricose, and 

 the body-whorl armed with long spines, as in imperialis 

 and chrysostoma* , both being connected to the coronated 

 melons by Broderipia and marmorata. The third 

 type is the V. Scapha, having the outer lip, as in the 

 StromhidcB, considerably angulated and dilated. The 

 fourth type is the V. angulata, whose aperture is very ef- 

 fuse ; and the spire very short, but pointed. Lastly comes 

 the Voluta magnificaa.ndfulgetrum t, where we once more 

 have the egg-shaped and inflated form of the melons, 

 together with their very thick apex, totally diflferent 

 from that of the Voluta ancilla, Sec, with which authors 

 have hitherto placed it. The Voluta alia and rubiginosa 

 follow this type, and blend it, in the most perfect manner, 

 with those we first enumerated. 



(95.) The passage from Voluta to our next 

 genus, Cymbiola, is opened by the rare V. mitis of 

 Lamarck ; which, by its general smoothness, its thick 

 spire, and a slight separation of the top of its outer lip 

 from the adjoining whorl, evinces a close affinity with 

 V. Scapha. The volutes now before us differ from the 

 former, in being stronger, less ventricose, and having 

 their spire much more lengthened : their whorls are 

 angulated, and are mostly armed with acute spines, or 



* Exotic Conch ology. 



t " In size and form this shell approaches nearly to V. magnijica."' — 

 Tank. Cat. p. 28. 



