OF SOUTHERN INDIA. 297 
1864, p. 20, and those described by Gabb in the Pal. of Calif., 1864, I, p. 105, etc., under the same 
generic name, we may mention a number of European cretaceous species, like W. ervyna, d’Orb., 
NV. Matheroniana, V@Orb., N. Rhodani, Pict. et Roux, and others. We shall give descriptions of the 
following six species from our cretaceous beds of S. India; Luspira pagoda, Forbes; Hu. Indrana, 
Stol.; Hu. rotundata, Sow.; Hu. spissata, Stol.; Du. lirata, Sow.; and Lu.Maria, V@Orb. Some of 
these species, like Husp. pagoda and others, are distinguished from others of the same genus by a some- 
what higher spire, which is specially prominent in young specimens, but this cannot be considered as 
of any great importance. Comparing, for instance, the recent Husp. duplicata with our Lusp. spissata, 
the difference in the height of the spire is almost trifling. 
7. Gyrodes, Conrad, 1860, (Jour. Acad. Nat. Sci. Phil., 2 Ser., [V, p. 289,) was 
first considered as a sub-genus of Natica, but subsequent researches have shown 
that it has been based on distinctions, not less characteristic than those of many 
other new genera. ‘The characters of Gyrodes are stated principally to consist in 
the globosity and thin structure of the shell, in the whorls being posteriorly flattened 
or canaliculated, and in the umbilicus being largely exposed, without any callosity 
on the columella or on the basis of the last whorl. 
If we were not in possession of large and apparently full grown specimens, we 
should have been very much inclined to consider the species of Gyrodes as Neverita 
in a young state, but with our present materials we believe the characters, above 
quoted, possess a generic value. The posterior flattening or canaliculation of the 
whorls is common to species of several other genera, and has therefore only 
relatively any importance. But the depressed or sub-globose form of the thin 
shell, the large umbilicus which often has in young specimens a crenulated, 
and always amore or less angular, peripherical edge, and lastly the want of a 
callosity on the inner lip, appear to be good characters of this genus. We do 
not know whether any living species of Natica belong tq it. Tertiary species 
are also not very numerous, and the cretaceous have as yet to be selected out of 
the large number of known species of Natica. 
Meek quotes in his Check-list of invert. foss., ete., (1864, p. 21,) six species, to which has to be 
added the Gyr. expansus, Gabb. (Pal. Calif. 1864, I, p. 108). European species like Nat. excavata, 
Mich., Wat. truncata, Pict. et Roux, and others appear also to belong to Gyrodes. We shall describe 
from S. India Gyr. pansus and Gyr. tenellus. 
8. Neverita, Risso, 1826, (H. and A. Adams, Gen. I, p. 208,) only differs from 
the former genus by the callous and twisted columella. The only cretaceous species as 
yet known is described by Gabb in the Pal. of Calif., 1864, I, p. 108, as Nev. secta. 
9. Mammilla, Schum., 1817, (Ruma, Chemnitz., H. and A. Adams, Gen. I, 
p- 209,) is allied to Gyrodes, but has a thick shell and the spire very short 
and pointed, the inner lip more thickened, and the volutions posteriorly not 
canaliculated or flattened. Gray in his catalogue of 1857, p. 49, retains Schumacher’s 
name Mammilla, and correctly quotes (in his list, ete., of 1847, p. 149,) Naticaria, 
Swains., as a synonym, while H. and A. Adams refer this last name to Neverita. 
They also accept for the genus the name Ruma, but I have been unable to procure 
any reference to the publication of this name. 
There are only a few tertiary species of Mammilla known, and also only very few from cretaceous 
deposits, like Nat. Pidanceti, Coqu. sp. (Pictet et Camp. Mat. Pal, Suisse, 3me. Ser., pl. 76, fig. 1), 
4D 
