OF SOUTHERN INDIA. 101 
Tt is, however, possible, that a fourth small anterior plait might exist, our specimen 
being in this respect not quite perfect. 
Locality —Near Serdamungalum, in a blueish calcareous sandstone, apparently 
rare. 
Formation —Trichinopoly group. 
d. Sub-family—MITRIN #. 
Mirrana, Gray’s Guide, 1857, p. 29. 
The animals of the muzrrz., so far as known, differ in many respects from those 
of the vozuriv», The foot is triangular, moderately expanded, the siphon long, 
without any auricles, the tentacles long, bearing the eyes near the basis, but usually 
within their length. The teeth are in three series, the central of which are broad 
and denticulated, but exhibiting great variations. It appears, that from a middle 
central tooth, resembling in all respects that of the rozvromrrrinz and sCAPHELLINE 
of Gray, furnished on each side with very small denticles (Mitra adusta), a gradual 
change can be traced to a broad many-denticulated central tooth, so that through 
the two above-mentioned sub-families the uzrerw seem in this respect also to be more 
(or at least quite as much) allied to the rozurm than to the Fuscrozaripz. With 
the latter family they have been classed by Gray, while H. and A. Adams unite them 
with the Cozvmertzip# in one family. We prefer the older classification in the 
family Vorurrpx to any of these, because the shell has through its consistency and 
shortness of the canal absolutely much more relation to other Vozurrz than to any 
FasctoLarip#, and as on the other hand the Cozvmezzz1pz have strictly no columellar 
plaits, but a plicated margin of the aperture only. 
None of the urrriv# are as yet known to have an operculum, like the larger 
number of the Vozuripa, while the Fascrozarip# have an ovate lamellar operculum 
much like the rusrv#, to the shells of which they. present certainly the greatest 
relationship. 
T have already noticed, that even with the separation of the vozvrouzrrins, 
-many shells of the wzzrzzv are in no other way separable from the rozvriyva, except 
in having the uppermost plaits the strongest and the anterior gradually smaller and 
thinner. There are indeed only a few exceptions to prevent this distinction being 
made quite practicable, and to cause other characters to be considered more conclu- 
sive, as, for instance, some species of Cylindra, Shum. and even Zierliana, Gray. 
That a distinction of the mwrrezz into several genera is quite as necessary as that 
of the vozurin», must be certainly acknowledged in considering such characteristic 
forms as Scabricola, Swains., Turricula, Klein, Zierliana, Gray and others, but the 
number of the restricted, or so called, sub-genera is by no means settled. We agree 
fully with Chenu, when he considers the genera and sub-genera of Swainson, H. and A. 
Adams and Gray as of equal value, and with probably few exceptions they seem 
to be so in reality, so that such a desirable separation and classification ought to be at 
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