LIST OF ILLUSTRATIONS. xv 



PAGE 



Fig. 62. Ostrea virginiana 264 



63; Diagrammatic representation of the segments of the 



leech ... ... 270 



64. Diagrammatic representation of the rings of a primi- 



tive crustacean .... 271 



65. Diagrams of hand of Crangon and of Astacus . 274 



66. Elbows of man and horse . . . 280 



67. Elbow of horse . 281 



68. Periptychus rhabdodon Cope, showing foot . . . 288 



69. Hind foot of Poebrotherium labiatum Cope . . 290 



70. Hind foot of three-toed horse 290 



71. United first bones of two middle toes of deer-antelope 291 



72. Wrist-joints at distal extremity of fore arm . . 292 



73. 'EXao^-\d\ii\. oi Crocuta viaculatay,. ... . 294 



74. Elbow- joint of chimpanzee . . 295 



75. Elbow-joint of Cervus elaphus • 296 



76. Cervus canadensis in motion . . 297 



77. Cervus elaphus 298 



78. Diagram of carpus of a Taxeopod, of a diplarthrous 



ungulate . . 299 



79. Raccoon pacing 299 



80. Rhinocerus unicornis carpus . . ... 300 



81. Equus caballus lore ioo\. 300 



82. Gazella dorcas . 301 



83 . Pes of Merychochcerus montanus and Bos taurus . 307 



84. Anterior feet of primitive Ungulata . 308 



85. Right posterior foot of Prothippus and Poebrotherium 310 



86. Manns of Artiodactyla . . 312 



87. Burrs on antlers of Cosoryx meatus Leidy 316 



88. Diagram of excursion of lower jaw in mastication 320 



89. Cervus, molars . 321 



90. Cusps of superior premolars and molars .... 322 



91. Two true molars of both jaws of a ruminant 323 



92. Sections of superior molar teeth 323 



93. Chirox plicatus Cope, palate and molar teeth 324 



94. Meniscoessus conquistus Cope, last two superior mo- 



lars . . . 325 



95. Lemur collaris, dentition .... . 326 



96. Esthonyx burmeisterii Cope, dentition . . . 328 



