LIST OF ILLUSTRATIO:r!^S. 



Plates. 



PLATE PAGE 



I. Figures and Diagrams of the Circulatory Centers of Vertebrata. Copied 



from Gegenbaur and His, mostly enlarged 60 



II and Ila. Figures of Lizards of the families Iguanidae and Agamidaa 



compared 97 



III and Ilia. Mimetic analogy in the colors and patterns in snakes of dif- 



ferent genera and species ........ 105 



IV and V. Series of Crania of Different Families of Tailless Batrachia 



showing similar stages of development. Original . . . 220, 221 



Explanation 222 



VI. Succession of Modifications of Feet of Diplarthrous Ungulata. Original 271 

 VII. Succession of Dental Forms, mostly of Ungulata. From Gaudry, Wort- 

 man, and Cope . . . 275 



VIII. Uintatherium rornutum Cope, restored, one twenty-seventh natural size. 



From Cope, Marsh, and Osborn 277 



IX. Anaptomorphus and Homo ; Cranium, Brain, and Teeth. Original, ex- 

 cept Figs. 8 and 9 from Allen 279 



X. Esequibo Indians. From photographs by Endlich .... 286 



XI. The Wrestler. From the Vatican . . .... 289 



XII. Venus of the Capitol 292 



XIII. Phenacodus primwvus Cope, Skeleton as found in matrix, one seventh 



natural size. Original 300 



XIV. Brains of Extinct Mammalia. Original, except Fig. 2 from Marsh . 308 

 XV. Bidonius mirabilis, Skull Profile. Original 338 



XVI. Didonius mirabilifs, Skull from below, one half the mandible removed. 339 

 XVII. Phenacodus vortmani, Skeleton as found in Matrix, two ninths natural 



size. Original 345 



XVIII. Hy(Bnodon horridus Leidy, Skull one half natural size. From Lcidy . 364 



Wo on- Cuts. 



7IQ. 



1. Diagram illustrating acceleration and retardation 10 



2. Diagram illustrating relations of genera of batrachia anura . . . 80 

 3 to 6. Diagrams illustrating development of genera of batrachia anura . 81 

 7. Same as Fig. 1 176 



B 



