RH/ET1C STAGE. 



287 



denudation, took place ; and at the same time this suggestion 

 accounts for several peculiarities in the nature of the fauna, which 

 have been found to be characteristic of the various isolated occur- 

 rences of these beds. 



For instance, in the small patches under the Loi-len range at 

 Lukhkai and Man Kio, the fossils, though 

 coSSoJT ° f ' OCal ^cognisable as belonging to the Napeng beds, 

 are all ill -developed, possessed of extremely 

 thin shells, and so stunted in size that they appeared to be hardly 

 worth collecting ; whereas many of the shells found in the broad 

 Napeng area are of large size, and some of them, those of the Gervil- 

 lias and Myophorias in particular, were evidently very massive. 

 This difference may be accounted for on the supposition that the 

 Lukhkai deposit was formed in a small, more or less isolated de- 

 pression, in which suitable food was scarce. 

 Sin - o e at again there is a very interesting occur- 



Nawngping. ° J & 



rence near Nawngping (Loc. 12, D 3) ; the first 

 station on the railway east of the Gokteik Gorge. At this spot, two 

 miles north of the station, Mr. Datta discovered, in a ' borrow pit ' beside 

 the line, a bed of shale exactly resembling that of Napeng, but with 

 a totally different assemblage of fossils, though there is no reason 

 to suppose that they do not belong to the same period. 1 The 



most interesting forms are fragments of decapod 



Crustacean remains. ... _ ... . * . 



Crustacea, among which Dr. H. Woodward, 



to whom they were submitted, has recognised the remains of prawns 

 and shrimps, but so imperfectly preserved that even the genera cannot 

 be determined. Fragments of a large Posidonomya, specifically indeter- 

 minable, and a small Lingula are also present. Further excavations 

 have been made at the spot both by Mr. Datta and myself, but we have 

 not been able to discover cither the extent or the thickness of the 

 deposit. On the opposite side of the line, however, I found what 

 appears to be the edge of a depression in which the clays may 



have been accumulated ; for the surface of 

 deposit? 1 * travertme the Plateau Limestone, at the point where 



a low ridge composed of it abuts on the line, 

 is covered' with a calcareous deposit in which numerous casts of 

 minute gastropods and some bivalves are embedded. At first 

 sight these seemed to be weathered out of the limestone, but on 

 examining thin sections of the latter under the microscope 1 could 

 detect no trace of an organism, and moreover the fossils havo been 



1 Crucial Report, Geol. Sun: Ind., 1899-1900, p. 



