POSTTERTIARY FAUNA FROM DEPOSITS OF BLITONG. 17 



NOTE vn. 



ON A POSTTERTIARY FAUNA FROM THE STREAM- 

 TIN-DEPOSITS or BLITONG (BILITONj. 



BY 



Dr. K. MARTIN. 



Professor of Geology. 

 jNovember 1880, 



Mr. C. de Groot has lately presented to the Museum a 

 collection of beautifully preserved shells etc., which he has 

 brought together among the stream-tin-deposits of Blitong , 

 in the district of Tandjoeng Pandang , mine N°. 8 , Djitjong. 

 Mr. de Groot tells me that these deposits are occasionally 

 regarded as tertiary, and he requested me to give a more 

 exact determination of their age, with the aid of the ma- 

 terial collected by himself. I was soon convinced , that the 

 fauna in question belongs to a very recent past, and for 

 this reason it may be more interesting for zoologists than 

 for palaeontologists. In the first place there can be no 

 doubt, that species occuring in posttertiary strata must 

 belong, when representatives of the same species are still 

 living, to the same zoogeographical area of the present 

 time, in which that species is now found. Consequently 

 they may serve to verify the localities from which shells 

 etc. are said to have come, both according to the zoolo- 

 gical literature and to the specimens in the musea. A change 

 may however have taken place in the distribution of the ani- 

 mals in these areas with regard to the several islands during 



Notes from the Leyden Museum, A^'ol. lU. 



