220 FISHES. 



These four regions diverge into two well-marked divisions, 

 one of which is characterised by the presence of Oyprinoid 

 fishes, combined with the development of Labyrinthici ; whilst 

 in the other both these types are absent. The boundary 

 between the Cyprinoid and Acyprinoid division seems to 

 follow Wallace's line, a line drawn from the south of the 

 Philippines between Borneo and Celebes, and farther south 

 between Bali and Lombdck. Borneo abounds in Cyprinoids ; 

 from the Philippine Islands a few only are known at present, 

 and in Bali two species have been found ; but none are 

 known from Celebes or Lombock, or from islands situated 

 farther east of them.-"- 



Taking into consideration the manner in which Cypri- 

 noids and Siluroids have been dispersed, we are obliged to 

 place the Indian region as the first in the order of our treat- 

 ment ; and indeed the number of its freshwater fishes, which 

 appear to have spread from it into the neighbouring regions, 

 far exceeds that of the species which it has received from 

 them. 



A. The Indian Eegion comprises the whole continent 

 of Asia south of the Himalayas and the Yang-tse-kiang ; 

 it includes the islands to the west of Wallace's line. To- 

 wards the north-east the island of Formosa, which also by 

 other parts of its fauna leans more towards the equa- 

 torial zone, has received some characteristic Japanese 

 Freshwater fishes, for instance, the singular Salmonoid 

 Plecoglosms. Within the geographical boundaries of China 

 the Freshwater fishes of the tropics pass gradually into 

 those of the northern zone, both being separated by a broad 

 debateable ground. The affluents of the great river tra- 



■" Martens (Preuss. Exped. Ostas. Zool. i. p. 356), has already drawn atten- 

 tion that a Barbel, said to have heen obtained by Ida Pfeiffer in Amboyna 

 (Giinth. Fish. vii. p. 123), cannot have come from that locality. 



