XVII] THE COMPARISON OF ITELATED FORMS 1071 



the corresponding coordinates of the very different pelvis of Apatornis 

 are represented in Fig. 533. In Fig. 534 the outUnes of these two 



6 7 8 cj 



Fig. 534. The coordinate systems of Figs. 532 and 533, with three 

 intermediate systems interpolated. 



coordinate systems are superposed upon one another, and those 

 of three intermediate and equidistant coordinate systems are 

 interpolated between them. From each of these latter systems, 



/ 7 i '- s 6 r 9 9 

 Fig. 535. The first intermediate coordinate network, with its 

 corresponding inscribed pelvis. 



SO determined by diredt interpolation, a complete coordinate diagram 

 is draw^n, and the corresponding outline of a pelvis is found from 

 each of these systems of coordinates, as in Figs. 535, 536. Finally, 



