316 LA TOUCHE: GEOLOGY OF NORTHERN SHAN STATES. 



This latter shell has since been examined by Mr. G. H. Tipper, 

 of the Geological Survey, who says that it also is a Planorbis, and 

 that it seems closely to resemble an upper Miocene form. The 

 appearance of these shells is extremely recent, the original shell- 

 substance being perfectly intact, though most of them are smashed 

 to atoms, while in some cases even the colours are preserved. 



In the Namma field Mr. Simpson found large numbers of gas- 

 tropods in some of the clay bands associated 

 ^Fossils— Namma coa - w ^ t ^ e CQa j seamSj especially in some of the 



ravines among the low hills on the west of 

 Xamma village (Loc. 3, H 2). Some of the shells are in a better 

 state of preservation than those mentioned above, but still not 

 sufficiently so to enable the species to be identified. Among them 

 my colleague Mr. Tipper, to whom I am indebted for the following 

 notes, has made out three genera : — 



"Melanopsis sp. The shell referred to this genus is generally quite well 

 preserved. In general shape and ornamentation it resembles M. Lorentkeyi, 

 figured by Andrussow ( Beitr. zur kenntniss des Kaspichen Neogen ; Mem. 

 Com. Geol. St. Petersb., N. S., Livr. 40, figs. 16-20) from beds of Pontian 

 age. It differs from this in the extraordinary thickening of the inner lip of 

 the aperture, this thickening forming a callous growth over half of the last 

 whorl." 



"Vivipara sp., characterised by three distinct smooth, rounded keels. On 

 the last whorl a fourth keel, much less prominent, can be distinguished. 

 This species differs from the present day keeled Vivipara quite distinctly and 

 seems to resemble very closely V. Pauli Brusina, from the Paludinen-Schichten 

 of Europe." 



" Hijdrobia sp. A small shell may be referred to this genus." 

 " Other genera are represented, but have not been identified chiefly on 

 account of the difficulty of clearing them from the matrix." 



In this basin the white kaolin -like clays exposed in a low hill 

 about half a mile north of Man-Se (Loc. 2, H 1) contain, besides 

 small gastropod shells, numerous impressions of dictyledonous 

 leaves and of grasses ; but none of these have yet been determined. 

 Leaf impressions are also found in the outcrop of a similar clay 

 mentioned on page 314 as occurring at Mankiin (I 2) in the Man-se-le 

 basin. 



Until the species of some of the shells found in these beds is 

 determined their exact horizon must remain 

 doubtful, for all the genera mentioned range 

 from the Miocene or even older periods, to Recent. The amount 

 of disturbance that the beds have undergone, which cannot all be 



