280 Mr. S. V. Wood on the Form and Distribution of the 



distribution of animal life during the cretaceous era, this collec- 

 tion is of the highest interest. It shows that during two suc- 

 cessive stages of that era the climatal influence, as affecting 

 marine animals, did not vary in intensity in the Indian, Euro- 

 pean, and American regions, whilst the later of the two [Verda- 

 chellam and Trinconopoly stage] had specific relations with the 

 seas of Europe which are absent from the earlier [Pondicherry 

 stage] . 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 connexion of the Indian and 

 European seas during the epoch of the deposition of the upper 

 greensand than during that of the lower. To this cause must 

 also be attributed the peculiar tertiary aspect of the Indian col- 

 lections, depending upon the presence of a number of forms 

 usually regarded as characteristic of tertiary formations, such as 

 Cyprcea, Oliva, Triton, Pyrula, Nerita, and numerous species of 

 Voluta } the inference 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 con- 

 nected with the tertiary, but that the genera in question com- 

 menced their existence earliest in the eastern seas." By the 

 expression I have copied in italics, the author, I apprehend, 

 meant a greater connexion of the seas by a more continuous 

 shore line, affording facility for migration of mollusca ; and this, 

 in order to join these regions, would necessarily be in an easterly 

 and westerly direction. The origin of the characteristic eocene 

 molluscous forms in the east, and their subsequent development 

 westerly, thus suggested by Mr. Forbes, seems to me to lend 

 support to the view that I have taken, of the connexion of the 

 seas of Western Europe with those of Eastern Asia, in the form 

 of a gulf stretching from Eastern Asia as far at least as the most 

 westerly limits of Europe, at the epoch when the sea again occu- 

 pied a part of the area which had been continent during the 

 intra-cretaceous and tertiary interval. 



If at the commencement of the tertiary period we find the 

 evidences of a tropical climate extending northwards to the 

 52nd parallel, due to the peculiar geographical configuration of 

 the period, how excessive may we conceive the climate of the intra- 

 cretaceous and tertiary period to have been, when a vast level tract 

 of desiccated sea-bottom, uninterrupted by mountain chains of 

 any importance, extended through the whole region between the 

 tropic of Cancer and the parallel of 50° N., from England 

 on the west to the Bay of Bengal on the east, and (from the 

 evidence of the eocene land-fossils) appears to have been con- 

 tinued westward in a lower latitude to America. Whether this 



