Dammerman: Fauna of the Krakatau Islands. 83 



found on Sebesy being only a little higher than on Krakatau and species, 

 the dispersal of which by the sea is difficult, being not strikingly more 

 abundant on Sebesy, proves, in my opinion, that at the eruption of 1883 

 the fauna of Sebesy was destroyed to the same degree as on Krakatau. 



The difference in the total number of animals, and especially the great 

 difference of species, can be attributed to Sebesy being so much nearer 

 the Sumatra coast, and to the much more normal flora than that of 

 Krakatau, as well as to the constant traffic in consequence of the reinhabiting 

 of this island in 1890. This all must be taken into account far more than 

 the possibility that more animals survived the eruption on Sebesy than on 

 Krakatau. 



However interesting the study of the fauna of Sebesy has proved, it 

 has not yet given us an answer to the question how far the fauna of 

 Krakatau is still abnormal and further research will have to be made to 

 solve this problem. 



IIL From where does the present fauna of Krakatau come and 

 how have the animals reached the island? 



An exact answer to the above question cannot be given for the moment 

 and has also to be postponed for future research. 



Most of the species found on the islands are widely spread, but of 

 others our knowledge of their distribution is still so limited that it is not 

 wise to draw conclusions. 



We collected several species on Krakatau and Verlaten I. which are 

 not known to occur either in Java or Sumatra. So Lepidodactylus lugiibris 

 is not recorded yet from these islands but from Riou and Borneo. 

 Mr. Leefmans has identified a Rutelid from Krakatau as Parastasia heterocera 

 Oh., a species mentioned as from the Andaman Islands only. The nearest 

 locality in which Siibaroptera longipes is known is the Tengger mountains 

 in E. Java; of Stylopyga picea, Borneo and Singapore. 



That all these animals should have come to Krakatau from such a 

 remote place is difficult to suppose. We must rather surmise that the 

 distribution of these species is very incompletely known. In this connection I 

 would observe that the fauna of Southern Sumatra, especially the Lampongs, 

 is poorly explored and many a species from Krakatau, till now only recorded 

 from far away, may probably be found at this near locality. 



With regard to the problem as to how the animals have reached the 

 islands, we can only make suggestions. We hope that a special study of 

 this subject later on will shed more light upon this matter. 



Considering different possibilities, the animals may have come to the 

 islands as follows: — by active flying or swimming; by the air or wind; 

 by ocean currents, and through the medium of other animals or man. 



Now computing how many winged animals there are on Krakatau, 

 Verlaten I. and Sebesy, we get resp. 81 "/o, 83 ^/o and 79 ^/o of the total amount. 



