( 247 ) 



cuUoetions of MoLiiNGRAAFL-" aiul Wing Easton it becomes ovidont 

 that ill tlie basin of tlie Mchiwi a deposit occurs which taken as a 

 whole is of the same age. This deposit evidently corresponds with the 

 formation stated by Eveuwijn to be tertiary, his statement however 

 was not sufficiently proved. The fauna of these beds exhibits diffe- 

 rent facies which is due in all probability to the quantity of salt 

 having vai'ied during the process of formation and also having been 

 present in greater or lesser quantities in different localities. A num- 

 ber of species {Melania and Paliidonuis) living in fresh water have 

 been found amalgamated with the species of Ci/rena and Corhiila 

 which are prevalent amongst these fossils and were inhabitants of 

 brackish water as also the species of Area which may have lived 

 in close proximity to the sea. This amalgamation would chiefly take 

 place during the rainy season. 



It is exceedingly difficult to settle the age of the strata in regard 

 to the character of the fauna as sketched above. A direct determi- 

 nation based solely on the occurrence of the species is impossible as 

 none of the above mentioned species corresponds with anj described 

 species either from India or the Malay Archipelago. Neither is it of 

 any use to compare these fossil species with the terrestrial shells of 

 Nias described by Woodward and which up to the present time 

 have been considered by others to be tertiary. During a recent visit 

 to London I have had an opportunity of studying these Xias forms 

 and feel assured that they decidedly are not tertiary but are, as 

 Woodward supposed, of a more recent date. 



A comparison W'ith the „intertrappean beds" of India, which con- 

 stitute a connecting link between cretaceous and tertiary, seems to be 

 of tlie greatest importance. Their fauna still allows relations to be 

 traced to the Larainie-group of North America and similar relations 

 also exist between the Laramie-group and the upper cretaceous of 

 Ajka in Hungary ; consequently this fauna was not from a geographical 

 point of view so well differentiated in those days as at the present 

 time. The fauna of tlie Melawi beds does not show any features to 

 correspond with that of the „intertrappean beds" the Laramie-group 

 etc., on the contrary containing only still living Indian genera amongst 

 which is the genus Paludoiiiii.i it resembles very closely in character 

 that of the present day. 



Separating from Paludonuts the genera FijrijiiUft'ra Meek and 

 Cosinia Stache which certainly do not belong to it, there remains 

 only a single group which must be considered one of the most 

 characteristic of the Indian fauna. The occurrence of the genus Pa- 

 bidoiniis is restricted to this area, being found in India, Further 



17* 



