300 LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



a description that would apply to portions of the Napeng beds, 

 discovered by Mr. H. F. Bellamy on the Lipis river in the Malay 

 Peninsula. These beds, which also contain several Myophorias as well 

 as Chlamys valoniensis, a characteristic Rhsetic fossil, have] been 

 referred by Mr. Newton to the uppermost Trias or Rhsetic ; and 

 it should be noticed that the composition of the fauna, consisting 

 as it does entirely of lamellibranchs, is similar to that of the 

 Sumat Napeng shales. Further to the south-east again, 



in Sumatra, some shaly limestones at Boekiet 

 Kamdoeng and Loerah Tambang, on the west coast of the island, 

 referred by Prof. Boettger to the Tertiary period, 1 have been shown 

 by Miss Healey to contain at least three species (named respectively 

 Hemicardium myophoria, Cardiia cjlobularis, and Pinna Blanfordi by 

 Prof. Boettger), which resemble three of the Napeng forms, Myophoria 

 napengensis, Cardita singularis, and Pinna cf. Blanfordi so closely 

 that Prof. Boettger himself has agreed that the Sumatra beds must 

 now be relegated to the Rhsetic. In these beds also the great 

 majority of the fossils are lamellibranchs. Thus it appears that 

 the equivalents of the Napeng beds had a fairly wide distribution 

 in the Eastern seas of the Rhsetic period, but that in each case 

 the fauna possessed a distinctively local character. 



It is perhaps hardly possible that a more striking instance could 

 be found of the difficulty that exists in determining the exact age 

 of a formation, when the only palseontological evidence at hand consists 

 of the casts of mollusca, and in the absence of clear stratigraphical 

 evidence, than this reference of beds really belonging to one and 

 the same horizon, on the one side to the Devonian, as in the 

 Shan States, and on the other to the Tertiary, as in Sumatra. 



No trace of the peculiar fauna of the Napeng beds has yet 

 been met with in the Himalaya. The rocks 



ffimak V a entS " ^ 1x1 that area o^^^g the Trias of S P iti and 

 Kumaon, referred by Dr. Diener and others 



to the Rhsetic period, 2 comprise the Para Limestone of Stoliczka, 3 



corresponding with the Dachsteinkalk of the Eastern Alps, and 



containing large numbers of Megalodon and Diccrocardium, but very 



1 Die Tertiarformation von Sumatra und ihrc Thierreste ; Patceontographica, Suppl. 

 II, Lief. 8, 9. 



2 Ladinic, Carnic, and Noric Faunae of Spiti ; Pal. Ind., Ser. XV, Vol. V, Mem. 

 No. 3, p. 150 ; Manual, Geology of India, 2nd Edn., p. 131. 



3 Geological sections across the Himalayan mountains ; Mem. Geol. Surv. Ind., Vol. 

 V, p. 62 ; C. L. Grisbach, Geology of the Central Himalayas ; Ibid, Vol. XXIII, p. 72. 



