324 Reviews—The Geology of India. 
associated with marine deposits of Oolitic or possibly Neocomian age. 
The Gondwana rocks are preserved as small patches mostly let down 
by faulting into the great crystalline mass of the Peninsula, whilst, 
isolated patches, including coal-beds, have been involved in the folded 
extra-peninsular area near Darjeeling and in Northern Assam. Next, 
above the Talchers, in peninsular India, comes the Damuda Series, 
which contain the most valuable Indian coal-seams; the associated 
rocks are all sandstones and shales, which sometimes attain a thickness 
of 10,000 feet. The ironstone shale stage is so called on account of the 
lenses of clay-ironstone which sometimes occur in sufficient abundance 
to supply a valuable iron-ore. The Panchet Series completes the, 
Lower Gondwanas, and is devoid of coal-seams, but has yielded reptilian, 
and amphibian bones to a considerable extent. 
The three above-named series constitute the lower division of the. 
Gondwana system, being cut off from the Upper Gondwanas by a 
marked stratigraphical break, accompanied by a contrast in fossil, 
contents. The plants of the Lower Gondwanas include many equi- 
setaceous forms, while those of the Upper Gondwanas show a preva- 
lence of cycads and conifers; also the species of common genera of 
ferns, as well as of other orders, are quite distinct.in the two divisions. 
The flora of the Upper Gondwanas is sufficiently abundant, and there 
are on this horizon great lava-flows, often amygdaloidal like those of 
the Deccan traps. The predominant flora of the Lower Gondwana. 
system, in which Glossopteris and Gangamopteris are prominent genera, 
has much closer affinities with the Mesozoic plants of Europe than 
with the plants of the Upper Coal-measures. This fact seemed at first. 
inconsistent with many other evidences pointing to an Upper Paleozoic 
age for the Lower Gondwanas. ‘‘ But the explanation offered by the 
earlier members of the Geological Survey of India, though for many 
years a stumbling-block to European paleontologists, has received 
conclusive support inrecent times . . . . With a boulder-bed of 
Permo-Carboniferous age at the base, and a marine intercalation of 
Jurassic and Neocomian forms near the summit of the Gondwana 
system, we have an inferior and superior limit of the time-scale over 
which to distribute its various series. A considerable fraction of the 
lowest beds must represent the Permo-Carboniferous, Permian, and 
Triassic periods; and yet the plants they contain show, when com- 
pared with European fossils, a predominating Rhetic and Jurassic 
facies.” 
The author further contends for the former existence of an old 
Indo-African continent, and claims that this supposed land-barrier is. 
rendered probable by a study of the distribution of Jurassic 
Cephalopods, whilst the Upper Cretaceous fossils demonstrate the 
existence of such a land-barrier still more completely. ‘‘ The great 
revolutions in physical geography which took place towards the end of 
the Cretaceous and during early Tertiary times resulted in the break 
up of the old Gondwana continent, and were followed by the rise of: 
the Himalayan range.” 
Whether there ever was such a feature in Permo-Mesozoic times as. 
this supposed continent, which is held to have united in biological 
affinities regions so remote from each other as India, Africa, and_ 
