190 LA TOUCHE : GEOLOGY OF NORTHERN SHAN STATES. 



the close of the Silurian epoch, as shown by the graptolites of the 

 Zebingyi beds, to the Productus and Fusulina limestones of Permo- 

 Carboniferous age. It is extremely likely that, when the Southern 

 Shan States come to be geologically surveyed in detail, it will be 

 possible to separate off these upper limestones, which are of a dif- 

 ferent texture and composition from the pure micro-crystalline dolo- 

 mites beneath, by a definite boundary line ; but in the Northern 

 States the upper limestones are so feebly developed, and their rela- 

 tions with the underlying rocks are so greatly concealed, that it 

 is at present impossible to say where one ends and the other begins, 

 or even whether they are conformable to one another or not. 

 „ m , At the western edge of the hills, near Tonbo 



.Sec tion .it Tonbo. ° . 



(Loc. 27, H 5), where the rock m places is 

 filled with specimens of Fusulina elongata, the compact and splint- 

 ery rocks containing the fossils seem to pass imperceptibly, both 

 horizontally and vertically, into the ordinary micro-crystalline 

 dolomites, and I could find no definite line of division. I have 

 therefore considered it advisable to include these upper fossiliferous 

 rocks for the present with the rest of the formation. 



Padaukpin Coral Reef. 



The exception, referred to above, to the almost universal .barren- 

 Middle Devonian ness m or g an i c remains of the lower part of 

 fauna : . this enormous mass of limestone, is of a truly 



Padaukpin. remarkable character. At the close of the 



field-season of 1900-01 I had halted at Wetwin, a village about 12 

 miles cast of Maymyo, in order to collect from some fossiliferous 

 shales which I had discovered during the previous season, when the 

 Myook, or native Magistrate of the place, brought me a handful 

 of fossil brachiopoda, among which 1 recognised a well preserved 

 specimen of Atrypa reticularis. On accompanying him to the spot 

 where these fossils had been picked up, just outside the western 

 gate of the neighbouring village of Padaukpin (Loc. 30, C 4), I 

 found the surface of the ground strewn with fragments of lime- 

 stone containing beautifully weathered out brachiopoda, corals, etc., 

 and single specimens also imbedded in the surface clay. One of 

 the first specimens that I picked up myself was an unmistakeable 

 Calceola sandalina, which at once fixed the horizon of the bed 

 within very narrow limits. The Myook then informed me that 

 these fossils had long been known to the villagers and were in some 



