130 It. B. Newton — Geology of the Malay Peninsula. 



sandstone clay-slate" in the Malay Peninsula whicli he thought had 

 not been previously noticed ; and subsequently the same writer 

 described the country as an elevated granitic axis with PalEeozoic 

 schists and slates at its base, mentioning also the occurrence of 

 detached masses of weathered limestone without fossils. 



In speaking of the gold deposits of Pahang, Mr. H. M. Becher ^ 

 stated in 18&3 that "the gold-quartz formation of Pahang traverses 

 an extensive series of sedimentary rocks. .... These rocks, 

 probably of Paljeozoic age, are for the most part thinly bedded 

 slates with some sandstones, and fewer dark-coloured, impure 

 limestone beds." Alluvial beds of modern origin were also 

 referred to. 



Dr. Koto- followed in 1899 with a brief allusion to this area, 

 and, quoting from a previous author, mentioned the occurrence of 

 " granites, old-looking sandstones, and slates," extending down to 

 Singapore. 



Finally, the present writer ^ described and figured theLamellibranch 

 remains discovered by Mr. H. F. Bellamy in a sandstone obtained on 

 the Pahang Trunk Eoad near the Lipis Eiver. A study of this fauna 

 proved it to be of Upper Triassic age ( = Ehaetic), the matrix being 

 termed a ' Myophorian Sandstone,' on account of the prevalence 

 of the genus Myophoria. These shells, the first recorded fossils 

 from the Malay Peninsula, were determined as under : — 



Chlamys Valomensis, Leymerie, sp. Mytilus allied to M. minutus, Goldfuss. 



Fteria Fahangensis, E. B. Newton. Mt/opJioria ornata, Miinster. 



Gervillia inflata, Schafhautl. Myophoria incequieostata, Klipstein. 



Pteroperna Malayensis, K. B. Newtou. Myophoria Malayensis, R. B. Newton. 



Actinodesma Bellamyi, K. B. Newton. Myophoria, sp. 

 Pleurophorus elongatus, ? Moore. 



Among unpublished observations it may be of interest to re- 

 produce, from a letter of recent date, an account of the geology 

 of the Eiver Tui District, situated in the Pahang division of the 

 Malay Peninsula, written by Mr. E. M. W. Swan, F.G.S., who is 

 carrying out mining operations in that area. The Tui is described 

 as a small branch of the Eiver Jelai, which joins the Lipis Eiver 

 at Kwala Lipis, from which place it is about ten miles due north. 

 Thanks are due to Mr. Swan's brother (Mr. Archibald A. Swan) 

 for permission to include this new matter in the present paper. 



" In order to explain the geology of the place where we are 

 working it is necessary to say a few words on the geology of this 

 part of Pahang, The common rock of the country is a clay slate, 

 or perhaps more properly shale, for the cleavage of the rock 

 coincides with the original bedding planes, although these have been 



1 H. M. Becher, "The Gold-quartz Deposits of Pahang (Malay Peninsula)" : 

 Quart. Journ. Geol. Soc., vol. xlix (1893), p. 84. 



* Dr. B. Koto, " On the Geologic Structui-e of the Malayan Archipelago " : 

 Journ. Coll. Sci. Univ. Tokyo, Japan, vol. si, pt. 2 (1899), p. 85. 

 1>V B,. B. Newton, "On Marine Triassic Lamellibranchs discovered in the Malay 

 Peninsula" : Proc. Malac. Soc. London, vol. iv (1900), pp. 130-135, pi. xii. 



