496 Guppy — West Indian Geology. 



IV. — Notes on West Indian Geology, with Eemakks on the 

 Existence of an Atlantis in the Early Tertiakt Period ; 

 AND Descriptions of some New Fossils, from the Caribean 

 Miocene. 



By R. J. Lechmere Guppy, F.L.S., F.G.S. 



^ QINCE the researches of Heer into the Miocene Flora of Swit- 

 ■ zerland have invested the theory of a Tertiary Atlantis with 

 some degree of probability, other observers have come forward with 

 arguments on the one hand which lend support to that hypothesis ; 

 whilst on the other hand it has been attempted to prove that the 

 facts (as to the presumed migrations of plants and animals) are to be 

 accounted for rather by a connection between Europe and America 

 through the Asiatic region. My examination of the Jamaican fossils^ 

 first led me to support a modification of the original view taken by 

 Heer, and in April, 1866, 1 communicated to the Geological Society a 

 paper bearing on the subject. That paper was read on the 20th of 

 June, 1866, and an abstract of it appeared in the August number of 

 this Magazine.^ I propose, on the present occasion, to make a few 

 remarks on the probability of the former connection between the 

 eastern and western shores of the Atlantic. 



It does not seem to me improbable that we shall ultimately have 

 to admit that the Tertiary Atlantis was, in all probability, only the 

 termination of a pre-Tertiary Atlantis, and that the physical changes 

 produced by the gradual disappearance of the Atlantic land, 

 and the emergence of land in other regions, gave rise to that 

 migration of species, the causes of which we now seek to explain. 



According to Dana, the North-American continent has been 

 receiving constant additions during the Paleozoic and Mesozoic 

 periods ; but he has not satisfied us as to the origin of the immense 

 amount of material necessary for the formation of so much land ; and 

 I would suggest the possibility of that material having been derived, 

 in part, from land which occupied some portion of the present 

 Atlantic area. Such land would have permitted the diffusion of 

 plants, while its shores afforded the means for the migration of 

 marine animals between America and Europe. Then, if the Atlantic 

 continent were of pre-Miocene date, and if its destruction and sub- 

 mergence began in Eocene times, we might be able to account 

 for the facts observed as to the distribution both of Eocene and Mio- 

 cene Invertebrata and Plants. Since the Eocene period the Alps, in 

 part formed of Nummulitic Limestone, have been upheaved, and it 

 may be assumed that an equivalent amount of depression took place 

 on some not very remote part of the earth's surface. The submer- 

 gence of the Atlantis continued throughout the earlier Tertiaries, may 

 have left but its higher points, as detached groups of coral islands, 

 in the later Miocene sea. Dana is of opinion that the Pacific land 

 has been depressed 6,000 feet in post-Tertiary times.^ It is, there- 



1 Quart. Journ. Geol. Soc. vol. xxii., p. 281. 



2 Vol. III. p. 373. Quart. Journ. Geol. Soc. Vol. xxii., p. 570. 



3 Manual of Geology, p. 587. 



