1074 THE THEORY OF TRANSFORMATIONS [ch. 



Among the species of Aceratherium, the posterior, or occipital, 

 view of the skull presents specific differences which are perhaps 

 more conspicuous than those furnished by the side view; and these 





I 



Fig. 538, Skull of Hyrachyus agmrius. After Osborn. 



differences are very strikingly brought out by the series of conformal 

 transformations which I have represented in Fig. 540. In this case 

 it will perhaps be noticed that the correspondence is not always 

 quite accurate in small details. It could easily have been made 



Fig. 539. Skull of Aceratherium tridactylum. After Osborn. 



much more accurate by giving a slightly sinuous curvature to certain 

 of the coordinates. But as they stand, the correspondence indicated 

 is very close, and the simplicity of the figures illustrates all the 

 better the general character of the transformation. 



