8i6 



INDEX 



Saw-fishes, 182. 

 Scales, acanthodii, 187. 



amphibia, 298, 366. 



anaspida, 127. 



birds, 432. 



cosmoid, 269. 



crocodiles, 419. 



crossopterygii, 256. 



ctenoid, 252. 



cycloid, 192, 252. 



dipnoi, 273. 



elasmobranchs, 176. 



osteolepids, 269. 



palaeoniscoid, 229. 



placoid, 129, 141, 158, 188, 252. 



pteraspida, 129. 



reptiles, 373, 411, 419. 

 Scarus, 252. 

 .Scent, amphibia, 299. 

 Schizocoele, 48. 



SCHOENHEIMER, R., 3. 



Sciaena, 218. 

 Scincomorpha, 409. 

 Sciuromorpha, 656. 

 Scturus, 657. 

 Scleromyotome, 94. 

 Scolopax, 519. 

 Scomber, 246, 256. 

 Scorpion-fish, 250. 

 Scyliorhinns, 130, 181, 250. 

 :Scymnog?iathns, 542. 

 Sea, changes in, 238. 



-cows, 720. 



-horses, 237, 246, 249, 256, 266. 



-level, changes of, n. 



-lion, 692. 



-squirts, 60. 

 Seal, 691. 



Segmentation, head, 148, 155. 

 Seining, 282. 

 Selachii, 175. 



Semicircular canals, cephalaspftia, 

 125. 



fishes, 216. 



hag-fishes, 109, 124. 



Lampetra, 109. 



pteraspida, 129. 

 Semnopithecus, 625. 

 Serranidae, 265. 

 Serridentinas, 716. 

 Sex hormones, actinopterygii, 266. 



amphibia, 341. 



birds, 476. 



elasmobranchs, 167. 



lampreys, 96, 120. 

 Sex reversal, birds, 476 

 Sexual reproduction, see Reproduc- 

 tion, Fertilization. 

 Sexual selection, birds, 502. 



Seymouria, 3 09, 359, 386, 539, 774. 



Sharks, 180. 



Shearwater, 493, 495. 



Sheep, 764. 



Shell, tortoise, 373, 393. 



Sherrington, C. S., 157. 



Shoaling, fishes, 227, 281. 



Shrews, 583. 



Shrike, 470, 485, 522. 



Sicklebill, 530. 



Sign stimuli, 480, 501. 



Silurus, 218, 237. 



Simia, 626. 



Simpson, G. G., 546. 



Sinanthropus, 645. 



Sinopa, 684. 



Siren, 358, 365. 



Sirenia, 720. 



Sivatherium, 758. 



Size, artiodactyls, 741. 



elephants, 709. 



eutherians, 576. 



horses, 737. 



reptiles, 421. 



whales, 666. 

 Skates, 182. 

 Skeleton, amphioxus, 29. 



Balanoglossus, 51. 



Lampetra, 85. 



See Vertebrae, Skull, Limbs. 

 Skin, actinopterygii, 192. 



amphibia, 298, 349, 352. 



amphioxus, 29. 



Balanoglossus, 51. 



birds, 432. 



elasmobranchs, 141. 



lamprey, 84. 



primates, 624. 



reptiles, 373. 



rhinoceros, 728. 



sexual, 624. 



tunicates, 60. 



whales, 667. 

 Skull, acanthodii, 187. 



actinopterygii, 193. 



amphibia, 325, 332. 



ant-eaters, 597. 



Archaeopteryx, 513. 



artiodactyls, 741. 



bird, 464. 



carnivora, 682. 



chelonia, 394. 



crocodiles, 419. 



development, 144. 



dipnoi, 272. 



edentata, 597. 



elasmobranchs, 142. 



elephant, 709. 



eosuchia, 402. 



