Origin of the Fauna of Celebes. 



123 



area of 6065 square kilom., since it takes up the rivers Lapa- 

 Lupa (La-Palupa), called in its upper waters Walannae, as 

 well as the Minralang and others. To the Tjenrana system 

 belong also the freshwater lakes Tempe and Sidenreng, the 

 latter covering 65 square kilometres. 



So extensive a river-system can but be conducive to the 

 development of a freshwater fauna. When, notwithstanding, 

 the freshwater fish-fauna of Celebes is poor in species (though 

 not in individuals), then the cause must lie in some other 

 direction. This has been already recognized by von Martens 

 and, as we shall see later, by Giinther. 



It might be thought that the present conditions are only 

 of comparatively recent date, and that formerly, from a 

 different configuration of the island, the river-systems reached 

 only a small degree of development. This brings us to a 

 region outside purely zoological considerations, which we 

 must nevertheless refer to later. At the same time emphasis 

 must be laid on the fact that another difference exists, more 

 important than the actual decrease in the number of species, 

 between the east and west portions of the Archipelago. 



This difference is most clearly to be seen by a comparison 

 of tables showing the occurrence of such fish in the Indian 

 Archipelago as are undoubtedly freshwater. The following 

 figures give the number of species of the different families on 

 the three large Sunda Islands, as well as on Celebes, Flores, 

 and Timor. Billiton and Madura are included in this enume- 

 ration, as well as Bali, which must not be omitted. 



* The CyprinodontidsB, although consisting largely of brackish-water 

 forms, are here iucluded under true freshwater fishes, since the genus 

 Haphchilus belongs entirely to fresh water. 



9* 



