320 ORTMANN — DISTRIBUTION OF DECAPODS [April 3, 



Australian fauna is derived from Asia (see von Ihering, 1894, p. 

 406, and Hedley, 1899). 



This connection between east Asia and Australia (Sino-Austra- 

 lian) is not well expressed in Jacobi's scheme. The apparent 

 reason for this is that Jacobi considered chiefly those groups of 

 animals (Mammals, Birds) which do not bear upon this question. 

 Nevertheless, some of his " regions of dispersal " come under this 

 head, namely, the ninth, tenth, eleventh and twelfth (Papuan, Far- 

 ther Indian, Philippine, southern Japanese ; see Jacobi, 1900, 

 pp. 208-210), and discussing the Papuan, he directly mentions the 

 Oriental origin of certain elements of it, thus" indicating its rela- 

 tion to southeastern Asia. 



Studying the tectonic configuration of the repective parts, we are 

 to remember that Australia belongs to the old, Palaeozoic Gond- 

 wana land of Suess (1888, p. 317 fT.), which also comprised Africa 

 and India. But we cannot refer to this old connection of Austra- 

 lia with India, since India in turn was not then united with the rest 

 of Asia, and since this connection was destroyed in very early 

 times, possibly in Palaeozoic. For a tectonic connection of Aus- 

 tralia and eastern Asia (excluding India) we have only evidence to 

 the contrary. 



On the other side, the eastern parts of present Asia, especially 

 China, northeastern Siberia, and Farther India, form a more or less 

 complete tectonic unit. Suess (1888, pp. 206-242) has shown that 

 this whole region consists largely of old archaic and palaeozoic 

 rocks, which form, in northern China, an old continental mass, in 

 the south a series of folded mountain ranges (p. 287), which con- 

 tinue into the mountains of Tonkin and Anam as far as the mouth 

 of the river Mekong. In this whole region no Mesozoic deposits 

 (with the exception of Rhaetic beds in Tonkin) are known. Ac- 

 cording to Koken, 1 a Triassic ocean extended from the region of 

 the Himalaya mountains and Central Asia to the shores of the 

 present Pacific, covering a large part of China. The latter may 

 have been land before Rhaetic times; but at present we have only 

 evidence that it was surely land in the Jurassic period. 2 



1 Neues Jahrb. f. Mineral., etc., 1900, Vol. 1, p. 196. 



2 See Loczy, L. von, Wissenschaftliche Ergebnisse der Reise des Grafen 

 Bela Szechenyi in Ostasien, Vol. 3, 1899; the Central-Chinese sea (south of the 

 Kuen-Lun mountains) disappeared at the end of Triassic and in Jurassic times. 



