448 



INDEX — GLOSSARY 



Trenton formation, fossils from, j6 ; geo- 

 logic age of. 36. 



Triarthrus, 285-290; T. becki, 286; 

 abdomen of, 287 ; antennules of, 289; 

 appendages of, 288 ; blood circulation 

 of, 289 ; cephalon of, 286, 287 ; com- 

 pared to a phyllopod, 285 ; digestive 

 canal of, 2H6 ; dorsal shield of, 287 ; 

 excretion of, 289 ; eyes of, 289 ; food 

 of, 288 ; growth of, 293 ; habitat of, 

 286, 287 ; muscles of, 288 ; nervous 

 system of, 289 ; pygidium of, 286, 287 ; 

 respiration of, 286, 289 ; restoration of, 

 17; skeleton of, 287; thorax of, 286, 

 287. 



Triassic, 407. 



Triassic fossils figured, 302, 347, 339. 



Triceratops prorsus, 363, 364; in evolu- 

 tion, 363. 



Trichina spiralis, 141. 



Trichoptera, 319. 



Triconodon, 378. 



Triconodonta, 378. 



Trilobita, 285-299; see trilobites and 

 Triarthrus. 



Trilobites, 285-299; appendages of, 

 291 ; blind, 291 ; cause of joints in, 

 290; daddy longlegs, 288; develop- 

 ment of, 292 ; eggs of, 292 ; enroll- 

 ment of, 291 ; eye-Hne in, 286, 291 ; 

 growth of, 292-293; habitat of, 290; 

 lace collar, 297 ; more primitive than 

 phyllopods, 293 ; muscles of, 291 ; 

 preservation of, 292 ; protaspis of, 

 292 ; related to phyllopods, 293 ; 

 relationship of, 293 ; relationship to 

 Limulus, eurypterids, scorpions, 311; 

 relationship to phyllopods, 293 ; repro- 

 duction of, 292; restoration of, 17; 

 sight of, 291 ; skeleton of, 291 ; sur- 

 vey of, 290-294. 



Trinucleus, 2S8, 296; T. concentricus , 

 2Q7; migration of, 23. 



Tritemnodon agilis, 380. 



Trochelminthes, 140, 141. 



Trochospere stage, in Annulata, 145 ; 

 in pelecypods, 217. 



Tube feet, movement of, 151 ; of 

 Asierias, 149; of echinoids, 7<5<!? ; of 

 starfish, 149. 



Tubicinella, 305. 



Tubipora, 128, 129, 135. 



Tubular ia, iii. 



Tubules, 184, 188. 



Turritella, 244, 246-247; T. mortoni, 



246, 247; evolution in, 847. 

 Turtles, 365, 366 ; see Chelonia. 



Uintatherium, 386; U. alticeps, 380; 

 U . mirabile, skull and brain of, 575. 



Ulmus americanus, 43. 



Ulna, of birds, 370, 372 ; of cat, 323, 327 ; 

 of mammals, 383, 386, 3Q4; of 

 reptiles, 338, 360, 362, 366, 367. 



Ulnare bone, of turtles, 366. 



Umbilicus, in cephalopods, 254, 265, 

 266, 267; in gastropods, 243. 



Umbo, in brachiopods, 188; in pelecy- 

 pods, 216, 229. 



Unciform bone, of cat, 327 ; of mammals, 

 395- 



Ungual phalanges, 395. 



Unguiculates, see Unguiculata. 



Unguiculata, 384; compared with Un- 

 gulata from early Eocene, 384; in 

 evolution, 399. 



Ungulata, see ungulates, 382-398. 



Ungulates, 382-398 ; ambulatory, reduc- 

 tion in, 385 ; browsing, reduction in, 

 385 ; compared with the unguiculates 

 from the early Eocene, 384 ; cursorial 

 increase in, 385 ; Eocene, closely 

 related to Creodonta, 379; even-toed, 

 396-398; evolution of, 384; function 

 of grasses in evolution of, 384, 385 ; 

 grazing, increase in, 385 ; odd-toed, 

 389-396; primitive, 384; principal 

 advance of, in enlargement of brain, 

 375, 385 ; subdivisions of, 385, 386, 

 389, 396. 



Unio, 228-229; U. luteolus, 229; age 

 of individual, 228; arching of female 

 shell, 288 ; composition of shell, 25 ; 

 corrosion of shell of, 229; develop- 

 ment of young of, 228; epidermis 

 of, 228; external protection of, 228; 

 habitat of, 228; sexes of , 228; siphons 

 of, 228, 229. 



Upper lip, in crustaceans, 280, 286, 287. 



Urea, see also excretion and waste under 

 the various classes; in Amoeba, 86; 

 in mammals, ii2\ in Protozoa, 86. 



Uric acid, in Annulata, 144; in Mam- 

 malia, 2,^2. 



