Hemisphere outvying the present inhabitants of those parts of the earth ? This interesting problem will have to be solved by future geologists.
Appendix : on the probable existence of an ancient Southern Continent.
The many similar forms of life, either fossil or recent, that are found scattered over various parts of different countries now so widely separated by the Indian and Pacific Oceans, seem to indicate that in very remote periods they must have been more intimately connected with each other than they are at present.
To those who believe that all the species of the same genus, and that in all probability all genera of the same family, have a common origin, it will appear almost self-evident that it must have been so. Thus remains of Dicynodont Reptiles and Labyrinthodont Amphibia are found both in India and South Africa, " affording," as Professor Huxley stated in a paper upon those from the former country, " new and interesting links with the fossil fauna of the Karoo beds of South Africa." In another paper he said, " There are two other forms of Labyrinthodonts which exhibit many similarities to the Micropholis. These are Brachyops laticeps of Prof. Owen, from Central India, and a new form allied to the Brachyops, but distinct from it, from Australia, the Bothriceps australis."
It is not only in the fauna of the Dicynodon formation, but in the flora also that connecting links are found ; thus a Glossopteris that has frequently been found in the Karoo and others from India and Australia are so nearly allied to each other that a high authority has stated that he " can find no specific distinction." With regard to this flora Mr. Tate, in his paper " On some Secondary Fossils from South Africa," says that it " presents -close analogy with that of the coal formation of Eastern Australia, and the plant- bearing beds of Burdwan and Nagpur in India. The characteristic plant in each of these deposits is a Glossopteris ; and it seems that the Indian, Australian, and South-African plants are specifically identical."
Amongst the fossil Mollusca of the succeeding Uitenhage formation we find many other such connecting genera. Thus the Exogyra, Trigonia, Cuculloea, Pinna, and Crassatella of the Sundays and Zwartkops strata find their representatives in Mauritius, India, and Australia, the Crassatella extending as far as New Zealand. With regard to the plant-bearing beds of this series, Mr. Tate writes*, — " Of the four species of Pecopteris, one is not satisfactorily distinct from P. lobata of India ; and two others are closely allied to P. indica, also from the Jurassic plant-beds of the Rajmahal Hills. . . . . . Asplenites lobata is common to these Indian and African strata ; and though, with one exception, they are distinct, yet, on the whole, the Jurassic plants of South Africa recall those of Scarborough and the Rajmahal Hills."
- Quart. Journ. Geol. Soc. vol. xxiii. p. 148.
