PART 4.] Waagen; GeograpMcal dutrihution of fossil orgamsnis in India. E83 
to occiipy inTariably a bathrological position below the basaltic flows; while 
certain grounds exist for regarding the above-qiToted dcjiosits in the Salt 
Kange and Sind as in part contemporary with the basaltic eruptions. In 
any case, according to their marine fossils, the Bagh beds represent a part of 
newer (middle) chalk. Their distribution is confined to the lower Nerbudda 
valley, where they appear in many places below the trap. Blanford gives full 
information about these beds in his excellent description of Western India.' At 
Cherakhan, the richest locality for fossils, the beds shew the following section : 
At the base, sandstone and conglomerate,'20 feet thick; above these, concretionary 
limestone with silicious excretions, 20 feet thick ; still higher up, clayey limestone, 
■with many fossils, ^'articularly echinoderms, 10 feet thick ; and finally, hard lime¬ 
stone, locally cellular, with numei'ous Bnjozoa and frag'ments of oysters, 10 to 
20 feet in thickness. The echinoderms were closely examined by Duncan,® -w^ho 
ascertained that the greater number of species wore identifiable with Upper 
Greensand species. It is doubtful -^rhether the sandstones and conglomerates 
which form the base of the above section should not bo regarded as a western 
extension of the Jabalpur or Mahadeva beds, 'which forms a connection between 
these and the Kachh plant beds. Southward of the Tapti river there are hardly 
any more localities shewing Bagh beds, so that the southern boundary of these 
beds may be assumed to bo here. Still farther south, we meet with no further 
marine mesozoic deposits on the western side of the Peninsula. On the east side, 
on the contrary, wm find the cz’etaceous rocks of the neighbourhood of Trichino- 
poly, which are so exceedingly rich in organic remains. 
The cretaceous deposits of Trichinopoly district have, it is true, been worked 
out palajontologically by Stoliezka in a very remarkable way; but it still appears 
that there are many points [of interest to be determined with reference to the 
stratigraphy of these formations. Our present knowlerlgo of the relations there 
existing is based mainly on H. P. Blanford’s compendious Monograph.® He 
recognizes three principal groiips, which are depo.sited on the primary rocks in 
overlajjping beds. The lowest, or Ootatoor, group begins with coral limestones, 
which are overlaid by fine sandy clays and sandstones with subordinate lime¬ 
stone. Above these follows the second, or Trichinopoly, group, consisting of 
sandy clays and conglomerates, which include, but only in the northern part of 
the area, numerous limestones abounding in fossils. The uppermost of the 
three groups is termed the Arialoor group; but at its base a sub-group, 
the Valudayur group), has been distinguished. The latter consists of limestones 
and conglomerates which pass up) into sandy concretionary limestones with 
numerous fossils. The age of all these beds was determined by tStoliczka as 
belonging to the period from the Cenomanian to the Seuonian.'* * It Avas thought 
' Blanford, W. T.: Mom. Geol. Surv. of India, VI; and Records Geol. Suiw. of India, V, p. 82. 
2 Uuncan; Quart. Journ. Geol. Soc., London, XXI, j), 349. 
^ Blanford, H. F. : Mem. Geol. Surv. of India, IV. 
* Stoliezka: Records Geol, Surv. of India, I, p. 59, and further on in many places. 
C 
