P ERMO-CARBONIFEROUS : PLATEAU LIMESTONE. 263 



Htengnoi. But some of the limestones associated with the Napeng 

 beds are very similar, as, for instance, the specimen from Loi-lam 

 (Loc. 23, E 3), a section of which is shown in Plate 15, fig. 2. 

 The Na-aw rock is crowded with elongated, oval, oolitic granules, 

 and contains in addition numbers of minute shells, and the spines 

 of echinoderms. 



The fossils collected at the three localities mentioned above, 

 _ . , , ., and described by Dr. Diener, are enumerated 



List 01 IOSSlls. . - - . . .. mllin l ■ l 



m the toilowmg list (I able 10), which also shows 

 the distribution of the species in other zoogeographical provinces. This 

 brings out the strong resemblance that exists between the Anthra- 

 colithic fauna of the Shan States and that of the Productus Lime- 

 stones of the Salt Range in the Punjab and of the Central Hima- 

 laya, and points at once to a great change of some kind in the 

 conditions that, up to this period, affected the relations between 

 the faunas of the northern and eastern coasts of Gondwanaland. 



The almost universal transgression of the Permo-Carboniferous sea 

 that took place at this time is a well established fact, but how and 

 where the barrier was broken down in this region is not quite 



clear. Indications have been met with that 

 tra P ns 1 ^e 0 s£n b0nifer0US the Permo-Carboniferous sea extended along 



the northern side of the present line of the 

 Himalaya as far east as the longitude of Assam ; for Dr. J. M. 

 Maclaren 1 discovered, in some boulders brought down by the Sub- 

 ansiri river in that province, a fauna which has been described by 

 Dr. Diener, 2 and was found to include such undoubted Anthraeolithic 

 forms as Productus cf. pustulosus Phill., Chonetes cf. carbonifera Keys., 

 a Dielasma allied to D. biplex Waag., Reticuhma cf. ince juilateralis 

 Gemm., etc. And since Permo-Carboniferous rocks are known 

 not to occur in association with the belt ol Gondwana sandstone 

 that runs along the flanks of the Himalaya on the north side of 

 the Assam valley, 3 it is probable that the boulders in which these 

 fossils were found come from the upper part of the Subansiri 

 gorge, beyond the main axis of the range. But it would have 

 required an entire submergence of the barrier to the north of Burma 



1 Geology of Upper Assam ; Records, Gcol. Surv. Ind., Vol. XXXI, Pt. 4, p. 186. 



2 Subansiri Fossils ; Ibid, Vol. XXXII, Pt, 3, pp. 189—198. 



3 P. R. Mallet, Geology of Darjiling and the Western .Duars ; Memoirs, Gcol. Sure. 

 Ind., Vol. XI, Pt. 1, p. 14 : H. H. Godwin Austen, Geology of part of the Dalla Hills ; 

 Journ. As. Soc. Bengal, Vol. XL1V, Pt. 2, v. 37 : T D. LaTouche, Geology of the Aka 

 Hills; Records, Gcol. Surv. Ind.., Vol. XVlfl, Pt. 2, p. 121. 



