402 Records of the Indian Museum. [Vol. XVI, 19 19.] 



any rate possess special characters adapting them to a peculiar 

 habitat, but the structural peculiarities are of an exactly opposite 

 nature. In the present case it is impossible to say whether the 

 special structures have a particular physiological function, or 

 whether they are merely highly developed in the one case and 

 rudimentary in the other. We do not know what are the effects 

 of this type of diverse evolution on the two species. 



