DEVONIAN SYSTEM : PLATEAU LIMESTONE. 



239 



mollusca, — gastropods and bivalves, — may be frequently seen in sec- 

 tion on the face of the locks, and though they are entirely con- 

 verted into crystalline calcite, merely their outlines being left, they 

 show that these forms of life must have been much more abund- 

 ant than one would be led to suppose from a study of the Padauk- 

 pin fauna alone. 



This consideration does not of course detract in any way from 

 the significance of the fact that we have here 



Significance of fauna. . , . ... , { , , 



a fauna as closely resembling that of the Litel 

 as does that of the middle Devonian of Devonshire, although 

 Padaukpin is separated from the former by an interval of 90 

 degrees of longitude and 35 of latitude. 



Nothing is yet known regarding the position of the Padaukpin 



bed in the great mass of limestone that sur- 

 f a H a riZ ° n ° f Padaukpin rounds it. The base of the Plateau Limestone 



is not exposed for a distance of many miles 

 in any direction, and the dips are so irregular and the existence of 

 concealed faults so probable that it is impossible to say what horizon 

 the reef occupies. The nearest f ossiferous beds are the shales of 

 Wetwin, now to be described, and the fauna of these is so entirely 

 different that it gives us no clue to the solution of the problem. 

 It might be solved if a similar bed were found in any of the 

 fault scarps, or on the sides of the gorges that penetrate the 

 plateau, but though my interpreter, who was greatly interested in the 

 fossils, and carried off several of those found at Padaukpin for 

 the edification of his Burmese friends, made many enquiries from 

 the natives, who are very keen prospectors, and though 1 have 

 searched many a scarp myself, we never succeeded in discovering 



distinct traces of similar fossils at any other 



in KTrukkyIirsca^ tlVCS localit y- Near the foot of the g reat Kyaukkyan 

 scarp, on the descent from Enghpo to Hkelawng, 

 ] 1 miles east of Padaukpin, I did indeed pick up, from the 

 talus, a single specimen of the cast of a large gastropod, not 

 unlike one of those found at Padaukpin, but quite unfit for deter- 

 mination. Unfortunately this happened before I had made the 

 discovery at Padaukpin, and I was never able to revisit the locality. 

 But it would be worth while to make a careful search along the 

 scarp here ; for if the bed from which this fossil came were found 

 in situ, it might be possible to ascertain its horizon, seeing that a 

 fairly complete section is exposed, from the Naungkangyis below to 



