GENERA OF SHELLS. 93 



Tlie volutœ are distinguished from the mitras by the 

 lower plaits on the columella being larger than the 

 upper, and by the obtuse and mammellated termination 

 of tlje spire. 



(a.) Shell ventricose, inflated. (Cymhiola.) 



V. nautica, diadema, arraata, ducalis, tessellala, ^thi- 

 opica. nielo, Neptuni, cymbium, oUa, proboscidalis, porcina, 

 scapha, Brasiliana. 



(b.) Shell oval, spiny or tuberculous. (Muricina.) 



V. irnpcrialis. pellis serpentis, vespertilio, niitis, nivosa, 

 serpentina. 



(c.) Shell oval, subttibcmiloiis. (Musicales.) 



V. hebfea, muèîca, clilorosina, thiarella, carneola, Guini- 

 aca, laRvigata, polyzonalis, fill va, sulcata, nodulosa. 



(d.) Shell elongate, ventricose, almost fitsiform. (Fusoidea.) 



V. magnifica, ancilla, Magellanica, Pacifica, fulminata, 

 Junonia, undulala, Lapponica. vexillum, valvacea, fesliva, 

 niitrœformis, nucleus. 



Margin ELLA. Shell ovale oblong, smooth, 

 spire short ; outer lip with a thickened margin. 

 Aperture subemarginate at base. Columella 

 plaited ; folds subequal. 



The marginelloS are smooth, polished shells, and 

 remarkable for the varix on the right lip. They are 

 distinguished from voluta by the equal folds on the 

 columella, by the aperture winch occupies almost the 

 whole length of the shell, by the callus on the right lip, 

 and by the scarcely perceptible notch at the base of the 

 aperture. 



(a.) Spire prominent. 



M. glabella, radiata. nubeculata, ccerulescens, quinquepli- 

 cata, limbata, rosea, bifasciata, faba, aurantia, bivancosa, 



