428 



INDEX — GLOSSARY 



Head shield, of ostracoderms, 33S ; of 



trilobites, 291. 

 Hearing, of cephalopods, 258 ; of crus- 

 taceans, 283 ; of mammals, 335 ; of 

 squids, 271. 



Heart, in gastropods, 242 ; see also under 

 the various classes. 



Heat, derivation of, in body, 332. 



Hedgehogs, 379. 



Heidelberg man, 400. 



Heliodiscus, 94. 



Heliophyllum, 132; H. halli, 12, ij2. 



Heliozoa, 93. 



Helix, 244, 250. 



Hemiptera, 320. 



Hemlocks, 73. 



Hepaticae, 44 ; geologic range of, 408. 



Herbivorous gastropods, 242 ; distin- 

 guished from carnivorous by means of 

 the shell, 242. 



Hermaphrodite, an animal or plant 

 having both sexes united in one indi- 

 vidual. 



Hermaphroditic, partaking of the 

 characters of an hermaphrodite. 



Herrings, 347. 



Hesperornis, 357; H. regalis, 371. 



Heterocercal tail fin, 338, 340, 344. 



Hexacoralla, 133-135. 



Hexactinellida, 97, 98, 102. 



Hexalonche microphcera, Q3. 



Hibernation, in gastropods, 242. 



Hind foot, of Eohippus, 303 ; of Equus, 

 393', of Hyracotheriiim, 393; of 

 Mesohippus, 303 ; of Protohippus, 393 ; 

 of Protorohippus, 393. 



Hind limbs, of Cetacea, 328; of Mali- 

 therium, 328; of Python, 328; of 

 Sirenia, 328; of snakes, 328. 



Hinge, in pelecypod shells,270, 216. 



Hinge line, of brachiopod shells, 188. 



Hinge plate, 216. 



Hinge teeth, cause of, 220. 



Hip, see sacral, sacrum. 



Hip bone, see innominate. 



Hipparionyx, 192. 



Hippopotami, 397. 



Hirudines, 142. 



Hirudo, 142. 



Hoactzin, 371-373 ; recapitulation in, 

 371, 373. 



Holly, 77. 



Holocene, 407. 



Holocephali, 343; autostylic, 339; 

 geologic age of, 343. 



Holoptychius, 345, 352. 



Holostei, 347; examples of, 347, 347. 



Holothurians, 171-172; food of 172; 

 fossils of, 172; geologic range of, 172, 

 409; habitat of, 172; spicules of, 172; 

 tentacles of, 172 ; tube feet of, 172. 



Holothurioidea, 1 71-172; see holo- 

 thurians. 



Homarus, 307 ; H . americanus, 27Q, 307 ; 

 habitat of, 307 ; molting of, 307 ; 

 number of eggs laid, 307 ; recapitula- 

 tion in, 307. 



Hominidae, 400. 



Homo, 400; //. diluvii testis, 353; H. 

 heidelbergensis, 400; H. primigenius, 

 400; H. sapiens, 400. 



Homoptera, 320. 



Honey-comb coral, 136, 137. 



Hood, in cephalopods, 232, 253, 255. 



Hoofed mammals, 382-398. 



Horns, exceptional development of, in 

 the extinction of the species, 375 ; hol- 

 low, 398 ; how former presence of is 

 recognized in fossils, 363 ; solid, 397. 



Horse family ; see horses. 



Horsehair worm, 141. 



Horses, causes of extinction of browsing, 

 375 ; changes during evolution, 393 ; 

 environment of, during evolution, 396 ; 

 evolution of, 392-396 ; extinction from 

 North America, 376 ; geologic range of, 

 392; habitat of, 374; in North 

 America, 375; modern, skull and 

 brain of, 375 ; recapitulation in, 394 ; 

 Texas, 383. 



Horseshoe crab, 277, 312. 



Horsetails, 48-50 ; fossil, 48-50 ; in 

 evolution, 55 ; silica in, 26. 



House fly, development of, 317-318; 

 eye of, 317. 



Howlers, 399. 



Humerus, of birds, 372 ; of cat, 323, 327 ; 

 of mammals, 325, 383 ; of reptiles, 338, 

 360, 362, 366, 367. 



Hydnoceras, 105. 



Hydrocorallinae, 121. 



Hydroids, 108, iii. 



Hydrorhiza, 109, iii, 117. 



Hydrospire, 148, 157, 158, 158. 



