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Jiecords of the Geoloyical Survey of India. 
[VOL. XI. 
probability be transferred to the end of the palseozoic era, or even possibly into 
it, and that the youngest jjlant beds reach up to the time of the Upjier Jura. 
For the latter fact there are positive data, as plant-bearing beds are found 
in Kachh united with others containing a very rich marine fauna. There is a series 
of beds 3,600 feet in thickness, which, as I have shown, represent the Jui’a from 
the Bathonian to the Portiandian in uninterrupted succession, in which every 
several bed is characterized by numerous species of Oephalojooda, is succeeded by 
a series of shales and sandstones -with land-plants, also some 3,000 feet 
thick, which in its turn is overlaid by Aptian beds.^ There can thus be no 
doubt about the bathrological position of the plant-bearing beds, and their age 
is thus indirectly fixed, that they must belong to the uppermost divisions of the 
juras or the lowest divisions of the cretaceous system. Dr. Feistmantel has 
recently endeavoured to settle the age of these jjlant beds directly, by working 
out the fossil plant-i-emains, and has arrived at the astonishing result that accord¬ 
ing to the plant species occurring in them, these beds must be regarded as 
liassic, or at most as middle Jurassic. The age-determinations thus deduced from 
the marine fossils and the plant-remains do not agree at all, indeed they lead to 
results of considerable divergence. Bach of the two age-determinations is right 
according to the present position of our knowledge, but which of the two 
approaches nearest to absolute truth can unfortunately not be decided, as for that 
purpose we should require to know the laws of development of the vegetable 
world from step to step as accurately as we know the succession of the marine 
molluscan fauna. We are here met by a contradiction that will only be solved 
by time, and perhaps in India. 
It is therefore rather difficult to understand that Dr. FeistmanteF should 
try and minimize the importance of his discovery by taking all imaginable trouble 
to explain the inadequacy of the Cephalopoda determined by me for the certain 
determination of the age of the beds, and to show that the remaining' mollusca 
contained in the Oomia beds should be determined as species belonging to the 
Bath Oolite. The way in which he proceeds to do this shows, indeed, at the 
fii’st glance, that he can hardly have ever studied and collected j urassic faunas 
in the field, for by such a jjroceeding as he applies, it might not bo difficult to 
bring the oolites of Portland Island into the Bathonian group. Ho overlooks en¬ 
tirely that Mr. Tate, on whom ho chiefly supports himself, has fallen into the same 
error, like the majority of French inquirers, in confounding the facies with the 
' See on the suhject of Stoliezka’s labours in this direction,—Blanford: Records Geol. Surv. 
of India, IX, pp. 80, 81. 
- reistmantel: Records Geol. Surv. of India, IX, p. 115, 4&c. Jahrb. fiir Min. Geol. u. Petref. 
1877, and elsewhere. Expressions such as, “ The Jura of Kachh was previously regarded as lower 
oolitic (and correctly so), etc,” scattered through PeistnianteTs letters, can only have been written 
with the intention, on the one hand, of discrediting Stoliezka’a truly admirable surveys and his 
sub division of the Kachh Jirra, and, on the other hand, of casting doubts on my determination 
of species, for it is simply impossible that such a number of Kelloway, Oxford, Kimmeridge, and 
Portland species could, if correctly determined, be found occurring anywhere in the Lower 
Oolite. 
