124 Memoirs of the Indian Museum. [Vor. VI, 
varieties recognized by Mr. Hornell, the one corresponding with Gmelin’s Turbinella 
vapa. According to Mr. Cossmann, ‘‘la spire un peu élevée, avec des nodosites trans- 
verses, très obsolètes, ressemble plutôt a celle de T. vapa, qu'à la spire tout à fait 
déprimée de T. pirum.’’ (Faune pliocénique de Karikal, Journ. Conch., Vol. L,, 1902, 
p. I30). Mr. Hornell has observed specimens of the modern Indian species in pleisto- 
cene or sub-recent formations near Rameswaram and Tuticorin. 
It has been above noticed that the oligocene species of India, Turbinella episoma, 
corresponds with a European fossil. The similarity between the oligocene faunas of 
India and of Europe is most remarkable, the percentage of European species in the 
case of the oligocene mollusca of north-western India, amounting to as much as 40 
per cent, indicating that the seas of India and Europe constituted, at that time, 
portions of one zoological province. In the case of the lower miocene beds of India 
with Turbinella affimis, and in those with T. preovoidea, the faunistic corres- 
pondence with Europe is very feeble, and the points of resemblance between the 
faunas of both regions finally disappear completely when we reach the horizon 
of the beds with Turbinella ovordea. The Indian Ocean and Mediterranean regions 
seem to have been as thoroughly disconnected in middle miocene times as they 
are at the present day. The presence of the Brazilian species becomes therefore 
all the more remarkable, and seems to indicate that, while direct communication 
was closed with the Mediterranean and eastern Atlantic, an easy interchange of 
species could nevertheless take place between the Indian Ocean and the regions 
now constituting the western Atlantic, or at least with the Caribbean Sea. It 
is worth noticing that Turbinella ovoidea occurs in a fossil condition in the Miocene 
of San Domingo, and it is highly interesting to recall, in this same connection, 
the observation made years ago by Duncan as to the extraordinary similarity 
between the lower miocene coral fauna of India and that of the West Indies. Natur- 
ally enough, Duncan was under the impression that the connection between India 
and the West Indies took place, in lower miocene times, across the Mediterranean and 
Atlantic. We find now, however, from a study of the mollusca, that the directness 
of the marine connection between India and Europe had been much impaired in 
lower miocene times, while in middle miocene times, when the communication was 
certainly completely cut off, we find a remarkable instance of specific identity with 
Brazil and the West Indies in the case of one of the commonest and most conspicuous 
mollusca. It should also be kept in mind that, in miocene times, the climatic condi- 
tions, throughout the Mediterranean region, had already become unfavourable to the 
growth of reef-building corals, and therefore, even had a free communication sub- 
sisted, the spread of these organisms through that region would no longer have been 
possible. 
It may very well be therefore that, already in lower miocene times, we should 
look to the east of India for the free communication that allowed the intermingling 
of the coral faunas of India and of the West Indies. 
In conclusion, the oligocene Turbinella episoma of India and Europe is not the 
ancestor of the Indian ‘‘ sankh,’’ or, if at all connected genealogically, the line of 
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