130 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



ON MARINE TRIASSIC LAMELLIBRANCIIS DISCOVERED IN THE 

 MALAY PENINSULA. 



By R. Buxlen Newton, P.G.S., etc. 



Read Uth May, 1900. 



PLATE XII. 



Rather more than two years ago Mr. H. P. Bellamy, C.E., of the 

 Public Works Department, Straits Settlements, presented to the 

 Geological Department of the British Museum some blocks of a light- 

 coloured sandstone containing casts and impressions of lamellibranch 

 shells, which he obtained from the Pahang Trunk Road on the Lipis 

 River, situated in the Malay Peninsula. 



The material is of unique interest from the fact that, so far as 

 can be ascertained, no fossils have hitherto been recorded from this 

 particular part of south-eastern Asia. Among the forms capable of 

 identification is Myophoria, which occurs abundantly throughout the 

 sandstone. The genus is intimately associated with Trigonia and 

 Schizodus ; the former ranging from Triassic times to the present 

 day, 1 the latter from the Carboniferous to the close of the Permian 

 period. Prom a stratigraphical point of view the occurrence of 

 Myophoria is of great value, since it belongs exclusively to the Trias. 

 On account of the prevalence of members of this genus in the rock in 

 question, the term Myophoricm Sandstone may well be bestowed on it. 



The sandstone is generally of a light fawn-colour, extremely soft 

 in places and easily scraped away; but other samples are of much 

 harder character and closer texture, and moreover present a reddish- 

 tinged appearance, with a burnt aspect suggesting original close 

 proximity to igneous rocks. Many of the shell remains are merely 

 moulds, although retaining, very perfectly, characteristic sculpture 

 and form, as clearly shown by wax impressions. It is remarkable 

 that the remains of Lamellibranchs alone are observable, no trace of 

 any other organisms having as yet been detected. The full list of 

 specimens identified comprises the following: — Chlamys Faloniensis, 

 Pleurophorus elongatus?, Pteria Pahangcnsis (n.sp.), Mytilus cf. minnttis, 

 Gervillia inflata, Pteroperna Malay ensis (n.sp.), Myophoria Malay ensis 

 (n.sp.), M. ornata, M. incequicostata, Myophoria sp. ?, Actinodesma 

 Bellamyi (n.sp.). One of the most important of these is Chlamys 

 Valoniensis, which has a wide geographical distribution and is 



1 The genus Triyonia has been generally considered to dale from the Lias, but 

 Dr. A. Bittner and Professor'Wohrmann, in support of D'Orbigny's views of 

 1849 (" Prodrome Paleoutologie," vol. i, p. 198), both regard the Triassic form 

 of Lyriodon Gaytani, Klipstein, as a true Trigonia; vide " Lamellibranchiaten 

 der Alpineu Trias," Abhandl. k.k. geol. Reichs. (Wien), Bd. xviii (1895;, pt. 1, 

 p. 89, pi. x, figs. 16-18. 



