RH.ETIC STAGE. 



299 



Table 12. 



Formation. 



Total No. 



New 



Percentage 



of species. 



species. 



of new 



species. 







Naungkangyi . 



47 



19 



40-5 



Namhsim 



41 



7 



170 



Zebingyi . 



20 



3 



15-0 



Padaukpin 



166 



26 



15-5 



Wetwin . 



30 



8 



26-6 



Permo-Carboniferous 



78 



5 



7-7 



Napeng Beds . 



81 



43 



53-0 



Thus, of the 81 species described from the Napeng beds 43, or 

 more than half, are new, while of the rest not more than three 

 have been identified with forms occurring elsewhere, and six can 

 only be compared with species already known, the remainder being 

 indeterminable. But even this statement does not completely ex- 

 press the peculiar nature of this fauna. In describing it Miss 

 Healey has found it necessary to establish two new families, the 

 Burmesiidw and the Dottidce, and to refer to them three new gen- 

 . era, Burmesia and Proloria to the former, and 

 so a ion o . j) a u a to the latter. From these facts alone 



it is evident that, in the interval between the deposition of the 

 Permo-Carboniferous limestones and that of the Napeng beds, great 

 changes in the relations of sea and land must have occurred, re- 

 sulting in the comparative isolation of the basin of which the 

 Shan sea at this time formed a part. 



How far this basin extended to the north and south is not 

 yet known. In Yunnan, Mr. Coggin Brown 

 has found beds containing some of the peculiar 

 Napeng fossils, including Burmesia, Palceoneilo, etc., resting, not 

 directly upon the Carboniferous limestone, as in the Shan States, 

 hut upon a series of red sandstones and shales with beds of coal 

 and salt which he considers to be of Pcrmo-Triassic age. To the 

 south it is interesting to find that one of the characteristic Napeng 

 species, Modiolopsis gonoides, has been identified by Miss Healev 

 „ , _ . , with a fossil, doubtfully described as Pleuro- 



Malay Peninsula. T , _,. ' - _ _ M , 



pnorus elongatus Moore by Mr. E. T. Newton, 

 which is found in some soft, light fawn coloured sandstones, 



Extension to Yunnan. 



1 Marine TriuHsie Luruellibruneks discovered iu tbu Mulay Peninsula ; 1'ioc. JJulac. 

 Sec. London, Vol. IV, p. 130. 



