OF SOUTHERN INDIA. 34: 
wet 
The following genera have been distinguished in this family :— 
1. Umbonium, Link, 1807 (Helicina, Lamck, 1801, ex parte; Pitonillus, 
Mont., 1810; Globulus, Schum., 1817, Rotella, Lamck., 1822). 
Sheli orbicular, depressed, polished ; columella thick, smooth; basis covered with 
a large, margined callosity ; outer lip thin, sharp on the edge. 
Lamarck did not at first distinguish the true Helicine from the shells for 
which Link in his Catalogue proposed the name Umboniwm. There cannot be any 
doubt as to the identity of Montfort’s Pitonillus and Schumacher’s Globulus with 
Umbonium, but the name Ptychomphalus of Agassiz appears to have been applied 
to different shells, which we shall again notice in the family PzravroromaRiD2. 
H. and A. Adams’ sub-generic distinction Ethalia does not appear to be well 
founded. A. Adams (Ann. mag. nat. hist., 1861, VIII, p. 308) treats Héhalia as a 
separate genus, but he also refers to it species like Eth. atomaria, which have the 
umbilical region perfectly covered by a callus. It seems to me, that the little 
species subsequently referred by A. Adams and Carpenter to this sub-generic 
division are generically not different from Teinostoma. From descriptions of other 
species, like Eth. omphalotropis, Adams (Ann. mag. 1863, XI, p. 266), it would 
appear that the principal distinction of Hthalia from Umbonium is the presence of 
an umbilicus, which is surrounded by a keel. If this were the real distinctive 
character of Ethalia there would be far more reason to separate it generically 
from Umbonium. The fossil species, like Trochus Moreanus, d’Orb. (Pal. frang. 
terr. jur, II, pl. 320, figs. 1-4) from the Coral-rag, and others, must then be referred 
to Hthalia. 
2. Photinula, H. and A. Adams, 1854 (Gen. I, p. 427—Photina, H. and A. 
Adams apud Gray, Guide, 1857, p. 141). Shell like Umbonium, smooth and polished, 
but usually spirally lineated ; the umbilical callus is impressed. This genus includes 
recent and fossil shells. ti 
3. Lewisiella, Stoliczka, 1868. Shell subconical, smooth or spirally striated, 
aperture roundish, margins continuous, columella solid, in the centre of the basis 
with a broad callosity, the edge of which is in front spirally twisted and 
joins the anterior portion of the mner lip by a conspicuous thickening. 
I consider the single, as yet known, liassic species Pitonillus conicus, d’Orb., 
as the type of the genus. Chenu (Man. I, p. 354) apparently attempts to reserve 
Montfort’s name Pitonillus* for the fossil species of the Umzowirpz, and Lamarck’s | 
name Rotella for the recent ones. This is, however, inadmissible, because Mont- 
fort’s name was unquestionably applied to the same generic type, for which 
Lamarck subsequently proposed the name Rofella. Besides d’Orbigny’s figure of 
P. conicus which Chenu copied is, as I have shown in my monograph of the 
liassic fossils of the Alpine Hierlatz strata (Sitz. Akad., Wien, 1861, Vol. XLII, 
p- 178, pl. 3, fig. 4), not correct in the most important point. The callosity does 
not cover the basis flatly as in the recent species of Umbonium; it is moreover 
raised, having a sharpened twisted edge in front, and joining the inner lip at its 
* The name Pitonellus is evidently only a misprint. 
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