5 62 



INDEX 



Theria, 524, 525. 



Thoracic vertebras, 335. 



Thorax, of insects, 241 ; of mammals, 



504- 



Thuricola, 53. 

 Thylacine, 528. 

 Thymus, 513 ; of birds, 476. 

 Thyroid, 513. 

 Thyroid glands, 476. 

 Tibia, 342, 416. 

 Tibio-fibula of frog, 416. 

 Tibio-tarsus of birds, 471. 

 Tick, 260 ; cattle, 260. 

 Tintinnidium, 49. 

 Tissues, 63. 

 Toad, 432. 



Toe, great, of frog, 410. 

 Toes, of birds, 487. 

 Tongue, of birds, 474 ; of frog, 417 ; 



of vertebrates, 344. 

 Torpedo occidentalis, 392. 

 Trachea, of birds, 476 ; of mammals, 



512 ; of reptiles, 347, 448. 

 Tracheae of insects, 248. 

 Trachelomonas, 37. 

 Trachelius, 49. 



Trachosphere of molluscs, 295. 

 Trachylinae, 102. 

 Trapezium, 502. 

 Trapezoid, 502. 

 Tree, genealogical, 9. 

 Trematoda, 134; ectoparasitic, 137. 

 Trichechidae, 540. 

 Trichina spiralis, 154. 

 Trichocysts, 46. 

 Triclad Turbellaria, 137. 

 Tridacna gigas, 280. 

 Trigeminal nerves, 382. 

 Trigger-hair, 95. 

 Trigonia, 280. 

 Triton nodiferus, 286, 294. 

 Trochanter, 471, 503. 

 Trochosphere of annelid worms, 201. 

 Trout, 395. 

 Tuatara, 437, 438. 

 Tube-feet, of Echinoidea j i70 ; of Holo- 



thuroidea, 173 ; of starfish, 160, 161. 



Tubipora musica, 119. 

 Tunic of ascidians, 315. 

 Turbellaria, 137. 

 Turbot, 397. 

 Turtles, 434, 438, 455. 

 Tympanic bones, 499. 

 Tympanum, 358 ; of frog, 408. 

 Tzetse fly, 58. 



Ulna, 341, 501 ; of birds, 469. 



Ulnare, 469. 



Umbilicus of feather, 460. 



Umbo of shells, 267. 



Umbrella, 95. 



Unau, 532. 



Unciform, 502. 



Ungulata, 526, 536. 



Unio complanatus, 265, 280; mar- 

 garitifer, 265. 



Urchin, sea, egg of, 60. 



Urchins, cake, 173; heart, 173. 



Ureter, 359; of frog, 427; of mam- 

 mals, 519 ; of shark, 384. 



Urethra, 359, 520. 



Urinary tubes, 248. 



Urine, 358. 



Urnatella, 181. 



Urochorda, 314; larva, 319. 



Urodela, 432. 



Urolophus testaceus, 390. 



Uropoda, 217. 



Uropygium, 457, 463. 



Uterus, masculinus, 520; of Nema- 

 toda, 154; of tape-worm, 140; of 

 vertebrates, 359 ; of worms, 133. 



Vacuole, contractile, 17, 36, 45 ; food, 



46. 

 Vagina, of leech, 211 ; of vertebrates, 



359- 521- 



Vagus nerve, 383. 



Valve, spiral, 374 ; of shark, 393, 402. 

 Valves, mitral, 510 ; semi-lunar, 510 ; 



of shells, 265. 

 Vane of feather, 460. 

 Variation, 3. 

 Vascular system of a fish, 378. 



