328 ORTMANN — DISTRIBUTION OF DECAPODS [April 



to the beginning of the Tertiary, but was destroyed in the older 

 Tertiary {I.e., p. 397). 



The same view is expressed by Koken : for the Lower and Upper 

 Cretaceous he gives to this peninsula about the same shape it had in 

 the Jurassic (Neumayr), and in the older Tertiary he draws — 

 instead of this continuous land-bridge — a chain of islands. 



There are not many cases where we possess such ample evidence 

 for the former existence of a land mass that has now disappeared, 

 at least as regards such a remote epoch. The chief arguments for 

 this land-bridge are taken from the character of the marine deposits 

 found at the supposed southeast and northwest sides of this penin- 

 sula, and they are especially convincing for the Cretaceous period. 

 The South-Indian Cretaceous, as it is found typically in the neigh- 

 borhood of Pondichery, is known similarly developed in Madagas- 

 car and Natal, and belongs to the ocean to the east and south of 

 this peninsula, while contemporaneous deposits of the western 

 Indian Ocean (in East Africa) and in northwestern India are 

 strongly contrasted to it, and are> related to the Mediterranen type. 

 We even may obtain further information as to the shape of this 

 peninsula. According to Newton and Boule, 1 the Jurassic beds of 

 the western coast of Madagascar belong to the Ethiopian Mediter- 

 ranean Sea (possessing the Mediterranean type), while the Creta- 

 ceous beds (Cenomanian-Senonian) of the same parts exhibit the 

 South-Indian type. This indicates that the Ethiopian Mediterra- 

 nean Sea extended, during the Jurassic period, farther south than 

 during the Cretaceous. The respective maps of Neumayr and 

 Koken agree well with this : according to Neumayr, the southern 

 extremity of Madagascar was united with Africa, while, according 

 to Koken, the connection was situated at its northern end. This 

 latter bridge continued to exist apparently during part of the 

 Tertiary time. We have seen above that the connection of East 

 Africa and [ndia continued up to the very beginning of the 

 Tertiary, and was destroyed soon after. This destruction, however, 

 affected only the parts between Madagascar and India, while Mada- 

 gascar itself remained connected with Africa : according to Jacobi, 

 up to the beginning of the Miocene. Lydekker 2 is of the opinion 



1 See review by Boehm in Neues Jahrb. f. Mineral., etc., 1897, Vol. I, 

 p. 489. 



2 A Geographical History of Mammals, Cambridge, 1 896. 



