INDEX 



735 



Difflugia, 20, 21, 22 



Digenea, 105, 112 



Digestion, 5 



Digestive ferments, 5, 428, 429, 656 



Digestive juice, 57 



Digestive system, of Birds, 624 ; of 



Echinoderms, 330 ; of Helix, 289 ; 



of Platyhelminthes, 96, 98, 104, 



101 ; of Vertebrates, 429 

 Digits, 520 

 Dinoflagellata, 34, 47 

 Dinornis, 631 

 Dinosauria, 604 

 Dinotherium, 686 

 Diomedea, 632, 634 

 Diphycercal fin, 447, 509 ; tail, 517 

 Dipleurula, 365 

 Diplopoda, 228, 231, 280 

 Dipneumona, 511, 518 

 Dipnoan, 507 

 Dipnoi, 473, 504, 517 

 Diprotodontia, 661, 663, 718 

 Diptera, 245, 248, 250, 282 

 Disc, 35, 36, 119, 326 

 Discoglossidae, 559, 562 

 Discoglossus, 562 



Discontinuous distribution, 226, 688 

 Distomum, 102, 104, 105 

 Diver, 634 

 Docidophryne, 551 

 Dog, 639, 640, 642, 649, 675, 676 

 Dog-fish, 465, 467 ; see Scy Ilium 

 Dolichoglossus, 386, 387 

 Dolphin, 681 

 Donkey, 690 

 Dorcatherium, 695 

 Dormouse, 701, 704 

 Dorsal blood-vessel, 144 

 Dorsal pore, 139 

 Dorsal sac, 315 

 Dorsal tubercle, 407 

 Down, 607 

 Draco, 586 



Dragon-fly, 175, 194, 246, 248, 252 

 Dromaeognathous palate, 629, 634 

 Dromaeus, 631, 633 

 Duck, 612, 613, 632, 634 

 Duckbill, 657, 658 

 Ductus arteriosus, 654 

 Ductus Cuvieri, 433 

 Ductus ejaculatorius, 244 

 Ductus endolymphaticus, 420 

 Dugong, 700 ' 

 Duplicidentata, 701, 725 



Eagle, 632, 634 



Ear, 64 ; ampulla of, 420 ; internal, 

 420; outer, 569; of Gasteropod, 

 293; of Vertebrates, 418, 419, 420, 

 444 



Ear-bones, 644 



Ear-cockles, 131 



Eared seals, 678 



Ear-shell, 293, 294, 296, 297 



Earth-pig, 669 



Earthworm, 147, 408 ; British species 



of, 157 



Earwig, 247, 251 

 Ecardines, 375 

 Ecdysis, 193, 194, 244, 567 

 Echidna, 656, 657, 658, 717 

 Echinarachnius, 356, 368 

 Echinaster, 326, 327, 331, 367 

 Echinocardium, 356, 368 

 Echinococcus, 110 

 Echinocyamus, 356, 368 

 Echinodermata, 326 ; classification of, 



367 

 Echinoidea, 344 ; subdivisions of, 355, 



368 



Echinus, 345, 346, 347, 351, 353, 355, 368 

 Echiuroidea, 167, 168 

 Ectoderm, 52, 179 

 Ectoplasm, 16, 19, 33 

 Ectoprocta, 380 

 Ectopterygoid, 477, 574 

 Edentata, 666, 719 

 Eels, 490, 491 

 Effodientia, 669, 719 

 Eft, 525 

 Egg-cell, 53 



_ 3, 8, 13 ; of Birds, 627 ; of Cla- 



docera, 206 ; of Cockroach, 243 ; of 



Teleostei, 491 

 Egg-sacs of Copepoda, 211 

 Elapidae, 591 

 Elaps, 591 

 Elasipoda, 360, 368 

 Elasmobranch embryo, 441 

 Elasmobranchii, 455; classification of, 



467, 512 

 Elater, 175 



Elephant, 684, 685, 686 

 Elephas, 685, 686, 722 

 Eleutherozoa, 366, 367, 368 

 Elk, 698 

 Elpidia, 369 

 Elytra, 236, 246 

 Embryo, definition of, 9 ; of Amphi- 



oxus, 392, 398 ; of Scyllium, 468 

 Emeu, 631, 633 

 Emulsion, 3 

 Emydidae, 597 

 Enamel, 454 

 Enamel organ, 643 

 Encystment, 19 

 Endocyclica, 355, 368 

 Endoderm, 52 

 Endoderm lamella, 60 

 Endoplasm, 16, 19 

 Endopleurite, 201 

 Endopodite, 179, 180, 209 



