OF SOUTHERN INDIA. 75 
of Mitra and Voluta lies in the dentition; the teeth in Witra being in three series, 
and in Voluta and Marginella in only one. I shall, however, further on notice a 
few points, which would appear to be more conclusive that Mitra ought to be 
classed with the Vozurrps, rather than with the F4scrozarm, as proposed by 
Gray. 
Viewing the large number of fossil species described under Witra and Voluta, 
we may without hesitation assert, that it is impossible to carry out such a distribu- 
tion into families, where often even the generic determination of species must 
remain doubtful. It would appear to give a sufficient exposition of these differences, 
if we accept four sub-families, viz., M4RGINELLINE, VOLUTINE, VOLUTOMITRINZ and 
wirrivé; and we shall therefore treat them accordingly. Deshayes recently* 
admitted Voluta, Mitra and Colwnbella into the family of Vorvrrpsz, and strongly 
advocates the exclusion of MJargimella. He criticises Dr. Gray’s classificatory 
changes very sharply. These, however, ought rather to be duly acknowledged, as 
indicating a steady progress in science; for it yet remains to be seen, how many 
followers Deshayes will find for his own classification. 
a. Sub-family,—MARGINELLIN A, 
The animals of Marginella and allied genera are no doubt closely related to 
those of the Crprzrp#, the tentacles being long, close together, bearing the 
eyes near their basis, or within the first half of their length, above and externally on 
small bulgings ; the siphon is of moderate length, simple at the base; the teeth on a 
lingual membrane, band-like, with numerous conical dentitions (resembling in 
form the lateral teeth of the crprarv); foot large, expanded, truncate in front; 
mantle enveloping the greater part of the shell and covering the same with an 
enamel coating ; no operculum. 
The shells are usually of small size, solid, ventricose, strongly involute, and, in 
full grown state, occasionally even convolute ; exterior surface mostly smooth ; ante- 
rior extremity not produced, only notched ; mouth linear, outer lip often thickened 
and toothed internally, ner lip always with wunerous plaits in all stages of growth. 
The m4arerverzrin® as restricted exhibit a great variety of form, and there 
appears every reason why the old genus Marginella of Lamarck ought to be sepa- 
rated into several smaller divisions (some of which are very characteristic, as stated 
by H. and A. Adams) under Marginella and Persicula. There is, however, no 
inducement for us to enter here into any discussion as to the value of those so-called 
sub-genera. Besides the species quoted by Adams under Marginella and Persicula, 
we think only those of Volvaria and Volvarina, Hinds, have to be admitted within 
the limits of this sub-family. The genus Volvaria ought to be restricted, as 
* Paris fossils, 1865, ITI, 572. 
