260 niOCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



two lowest stages, tlie Nari and Gaj, "wliich respectively correspond 

 ■with the Staiupian and Aqiiitanian, and this correlation is also 

 supported by the stratigraphical data. For stratigraphical reasons 

 the newest age that can be assigned to the Hinglaj is Vindobonian. 

 It is evident, therefore, that the proportion of llecent species is much 

 greater than in European strata of the same age. The Gaj, which is 

 essentially Aquitanian, contains a ])rop()rtion of living forms which 

 is as great or greater than that met witli in tlie uppermost Miocene 

 of Italy, while the Hinglaj, if judged by the European standard, 

 Avoiild have to be regai'ded as Pliocene. Yet the Hinghaj Beds are 

 uncouformably overlaid by the Siwalik formation, whose lower strata 

 contain mammalian remains of Miocene age. 



A similar divergence from the European standard had already been 

 noticed in 1879 by Professor Karl Martin in his study of the fossil 

 Miocene fauna of Java (^Tertiur^chichten anf Java, general part, ]). 24). 

 The figures arrived at by Martin are as follows (loc, cit., p. 28) : — 



Martin was under the impression that the Miocene fauna of Java 

 corresponds essentially with the Gaj. Little is known of the 

 stratigraphy of the deposits that have yielded the Javanese fauna, 

 but from a comparison with the fauna of jS^orth-Western India, which 

 contains a very large number of species identical with fossil Javanese 

 forms, it is evident that the Java fossils were not derived all from 

 one zone, but from several successive horizons. The greater number 

 evidently were derived from strata situated on the same geological 

 horizon as the Lower Hinglaj, but there is a considerable admixture 

 of typical Gaj and Upper Hinglaj species, showing that both these 

 horizons are also represented, though to a minor extent. 



The explanation of this difference is to be sought in tlie chequered 

 career of the European seas, both geographical and climatic, during 

 later Tertiary times, as compared with the uneventful history of the 

 Indian Ocean during the same period, which must have allowed 

 therefore a much more gradual evolution of the marine fauna. 



When we compare the Indian fossil faunas with European fossil 

 faunas of the same zones, we observe a rapid decrease of the proportion 

 of identical species in the stages following the Kari. The proportions 

 are as follows : — 



European Percentage of 



species. European species. 



Nari . . . . 48 . . . 41-0 

 Lower and Upper Gdj . 17 . . . 12"4 

 Lower Hinglaj . . 4 . . . 5 "4 



Upper Hingldj . . 3 . . . 6 "5 



The fossil fauna of the Kari I'esembles the Oligocene fauna of 

 Europe so closely as to constitute an eastern extension of the same 

 zoological province, indicating great freedom of oceanic communication. 



