208 SECTIONAL ADDRESSES. 



furnished by the Brachiopods, a group which Prof. Schuchert ' practically 

 ignores.' ' If the Brachiopods of the Amb beds {i.e. essentially the Lower 

 Productus Limestone) are considered, then one of the noticeable features 

 is the afl&nities of the fauna to that of the Uralian [Upper Carboniferous] 

 and Artinskian [Lower Permian] of the Urals.' The evidence of the 

 Brachiopods ' would point to the Amb series being of Lower Permian age 

 at the latest, and I cannot agree with Schuchert 's reference of these beds 

 to the Upper Permian.' It follows that the underlying Speckled Sand- 

 stone, classed by Schuchert as Middle Permian, are ' of high Carboniferous 

 age ' : ' hence,' he continues, ' the fauna of their lower part, i.e. Eurydesma 

 cordatum, E. globosum, Conularia laevigata, etc., is also of Upper Carboni- 

 ferous age.' In the same letter Dr. Thomas quotes the following statement 

 by Prof. Schuchert : ' The interregional correlations are made, however, 

 not so much from the evolution of the Brachiopods as from that of the 

 Ammonites,' and, Dr. Thomas adds — ' But there are no Ammonites in 

 the succession under dispute in New South Wales, nor are there any in 

 the whole Salt Range Series between the boulder bed and the base of 

 the Xenaspis carbonarius zone ; nor in South Africa, nor in South 

 America.' In his discussion of the age of the Australian beds, Schuchert 

 includes in a list of fossils Agathiceras microtnphalus, which he regards as 

 a member of an ammonoid fauna. Dr. Thomas says : ' A few years ago 

 I examined together with Dr. Spath the specimens in the British Museum 

 sent over as that species. They could equally well be Bellerophontids. 

 At the same time Dr, F. W. Whitehouse, of Queensland, examined 

 as many specimens as he could in Australia. I do not know if 

 he was able to examine the type-specimen, but in a recent letter to me he 

 stated that about three-and-a-half years ago he published in Australia 

 a note to the effect that the fossil called Agathiceras micromphalus is not 

 an ammonoid but a bellerophontid.' Dr. Thomas, in another part of his 

 letter, points out that Schuchert does not attempt an analysis of the 

 fauna of the Australian Irwin River beds, and adds : ' I am quite con- 

 vinced that the glacial beds there are of Upper Carboniferous age and that 

 Paralegoceras Jacksoni is of Uralian age too. Nor does he consider the 

 tillite of Barreal, Argentina, which Reed has shown to be of Uralian age.'^ 



I have quoted only in part from Dr. Dighton Thomas's letter in the 

 hope that he will publish in full his criticisms of Prof. Schuchert 's views. 



In another region, the district of Spiti in the Punjab, some fragmentary 

 plant remains including a Rhacopteris, identified by the late Prof. Zeiller 

 as Lower Carboniferous, were foxmd in beds assigned to the Po series. 

 Above these rocks occur shales with marine fossils, which are regarded as 

 homotaxial with the lower part of the Zewan series of Kashmir, and 

 probably either Lower Permian or Upper Carboniferous in age. In the 

 Peninsula of India the beds which contain relics of the Glossopteris Flora 

 and the Talchir tillite are almost entirely of freshwater or terrestrial origin, 

 but in 1921 some marine fossils were found in Central India above the 

 Talchir boulder bed. Prof. Schuchert, in referring to this important 

 discovery, expresses the opinion that the marine beds may be ' of the 

 earliest Productus limestone time,' that is in his view Upper Permian. 



1 See Du Toit : A Geological Comparison of S. America with 8. Africa. (Carnegie 

 Instit., Washington, 1927.) 



