Forbes on Cretaceous Fossils from Southern India. 265 



Oolitic fossils occur as of upper green sand. The resemblance 

 between the Ammonites of this part of the collection and those 

 of Castellane, in the south of France, is very remarkable, though the 

 specific identity of any of them is doubtful. Having seen no account 

 of the Conchifera of the Castellane beds, I cannot say how far the 

 analogy is borne out among the bivalve Mollusca among the Indian 

 species, of which there are many very peculiar forms. 



5th. Considered in regard to the distribution of animal life during 

 the Cretaceous era, this collection is of the highest interest. It 

 shows, that during two successive stages of that era the climatal in- 

 fluence, as affecting marine animals, did not vary in intensity in the 

 Indian, European, and American regions, whilst the later of the two 

 had specific relations with the seas of Europe, which are absent 

 from the earlier. The cause of this remarkable fact is not to be 

 sought for in a more general distribution of animal life at one time 

 than at another, but rather in some great change in the distribution of 

 land and sea, and in a greater connection of the Indian and Euro- 

 pean seas during the epoch of the deposition of the upper green- 

 sand, than during that of the lower. To this cause must also be 

 attributed the peculiar tertiary aspect of the Indian collections, 

 depending on the presence of a number of forms usually regarded 

 as characteristic of tertiary formations, such as Cyprsea, Oliva, 

 Triton, Pyrula, Nerita, and numerous species of Voluta, the infer- 

 ence from which, since not one of the species is identical with any 

 known tertiary form, should not be that the deposits containing 

 them are either tertiary or necessarily connected with tertiary, but 

 that the genera in question commenced their appearance earliest in 

 the Eastern seas, which, when we recollect that in those very seas 

 at the present day, are found the great specific assemblages or capi- 

 tals of those genera, whilst they have either disappeared or have 

 few representatives in the seas of other geographical regions, is 

 exactly what we should expect, & priori, to find. This fact would 

 go far to support the theory, that genera, like species, have geogra- 

 phical birth-places as well as geographical capitals. 



The fact, that of the few species found in the Indian cretaceous 

 beds which are common to the same beds in distant regions, the ma- 

 jority are such as range through several deposits of different ages, 

 supports the probability of a law which I have elsewhere indicated, 



