Explanation of the Map 

 On the map are given the easterly boundaries of a num- 



line; and the westerly boundaries of some Australian 

 forms, shown by broken lines. Map No. 1 is based on f resh- 

 water rHios; Xo. 2, upon amphibians; Xo. upon mam- 

 mals. On all three maps, Wallace's line is shown as an 



the lines bounding the ranges of other classes that it has 

 no value as a zoogeographic boundary. The Indian 

 animals in very many cases reach to the eastward of it, 

 while the Australian forms do not reach out to it, so 

 naturally do not cross it. One sees at once that the Indian 

 and Australian components of the fish fauna are widely 

 differentiated; and that among amphibians and mammals 

 it is necessary to take nearly the entire eastern half of the 

 aivliipebmo a- the transition region which we have men- 

 tioned before. 



