422 



INDEX 



Diomedea exultans, 293 * 



Diphy cereal caudal fin, 104, 105 *; in 

 Pleuracanthus, 121 



Diplacanthidae, 110, 119 



Diplocaulus, 180 *, 181 



Diplosoma, 55 * 



Dipneusti, 107, 112, 154-159 



Dipnoi, 112 



Diprotodontia, 345, 357, 358 *, 359 



Dipterus, 156 



Dipus jaculus, 372 * 



Discoglossidse, 198, 199 



Dissorophus, 181 



Distcechurus, 357 



Divergence, law of (adaptive radia- 

 tion), 19 



Diving origin of flight, theory of, 275, 

 276 



Dodo, 304 



Dog-fishes, 113 



Dog-sharks, 112 



Dolichoglossus kowalevskii, 62 * 



Doliolum, 56, 57 *, 58; life cycle of, 

 57 *, 58; D. tritonis, 57 * 



Dollo, 235 



Dominance and subordination, 11 



Draco volans, 248 *, 249, 250 



Drepanaspis, 169 *, 170 



Dromceus novce-hollandioe, 285 * 



Dromicia, 357 



Dromocyon, 341 *, 342 



Dromotherium sylvestre, jaw of, 337 * 



Ducks, 297 



Dugongs, 396, 397, 398 * 



Duplicidentata, 371 



Eagle, golden, 298 



Eagle ray, 124 *, 125 



Echidna aculeata, 348, 349 * 



Echidnidsa, 345, 348-350 



Edaphosaurus, 216 



Edentata, 345, 373-377; extinct, 377 



Eels, 111, 140, 141; electric, 140 



Eel-like form, a criterion of racial 

 senescence, 21 



Eggs, of Amphioxus, 42; of tunicate, 52; 

 of myxinoids, 91; of lamprey, 94; of 

 fishes, 101; of Teleostomi, 128; of 

 sturgeons, 133; of Amia, 134; of 

 fishes, 163, 164 *, 165; of ling, 165; 

 of Lepidosteus, 165; of frog, 204; of 

 Chelydra, 236; of Aromochelys, 238; 



of Aspidonectes, 242; of Ostrich, 283; 



of bird, 315 * 

 Elaps, 257 



Elasmobranchii, 112-127 

 Elasmosaurus, 218 *, 219 

 Electric organs, of rays, 123 

 Electric rays, 123, 124 * 

 Elephant birds, 287 

 Elephantidse, 394, 395 *, 396; extinct, 



396 

 Elephas indicus, 394, 395*; E. afri- 



canus, 394, 395 * 

 Eleutherodactyli, 310 

 Elk, 390, 391 * 

 ElopidaB, 138 

 Emberiza, beak of, 282 * 

 Embryo, of chick (35 Somites), 318 *; 



five days old, 321 *; of Hypsiprym- 



nus, 405*; of Phascolarctus, 405*; 



of Perameles, 406 * 

 Embryonic membranes, of reptile, 212, 



213*; of bird, 319, 320*, 321; of 



marsupials, 405 *, 406; of rabbit, 



410 *; of man, 411 * 

 Emeu, 284, 285 *, 286 

 Emys orbicularis, 235 * 

 Endocrine glands and racial senes- 

 cence, 22 

 Endostyle, 37, 38, 40*, 51, 96; of 



Ammocoetes, 95, 96 

 Engystoma carolinense, 202 

 Engystomatidse, 202 

 Enteropneusta, 33, 84, 85 

 Environment in relation to evolution of 



characters, 28, 30 

 Epanorthida^ 357 

 Eptesicus fuscus, 364 

 Equidse, 392 



Equus, 392; E. burchelli, 393 * 

 Erinaceidae, 362 

 Erinaceus, 362 

 Eryops, 180 *, 183 

 Esocidae, 142 

 Esox masquinongy, 142 

 Eudyptes chrysocoma, 293 * 

 Eulampis jugularis, 307 * 

 Eumetopias jubata, 369 * 

 Eunotosauria, 234 

 Euphractus sexcinctus, 376 

 Eusuchia, 242 



Eutheria, 345, 352; definition, 352 

 Evans, A. H., 289 



