INDEX. 
Touch, organs of, in mollusks, 
250 
Toxodontia, 600, 629 
Trachymeduse, 62 
Trachystomata, 478, 487 
Transmission, law of, 11 
Trematodes, structure of, 104, 
121 
development of, 105 
pupa of, 107 
Trichiua spiralis, 127 
Trichocephalus dispar, 127 
Trigla, 448 
Trigonocephalus, 499 
Trilobita, young, 303 
Trinucleus, young of, 308 
Triton, 478 
Trivia californica, 239 
Trochilus colubris, 551 
Trochosphere, 233, 244 
of polyzoa, 144 
of worms, 105 
Trochus, development of, 244 
Trout, 452 
Trunk-fish, 462 
Trygon, 424 
Tubularia, 60 
Tubipora, 85 
Tunicata, development of, 393, 
401 
structure of, 386, 405 
Turbellaria, 100, 120 
Turdus migratorius, 556 
Turkey, wild, 546 
Turtle, green, 510 
hawkbill, 510 
loggerhead, 510 
sea, 510 
snapping, 510 
soft-shell, 510 
swamp, anatomy of, 506 
tortoise-shell, 510 
Tylenchus scandens, 128 
Tylos, 286 
721 
Typhlocolax acuminata, 103 
Tyroglyphus sacchari, 341 
ULocyaTaus arcticus, 80 
Umbellularia groenlandica, 86 
Ungulata, 600, 629 
Unio complanatus, 224 
Urchins, sea, 199 
Urodela, 478, 484, 488 
| Urolabes palustris, 128 
Ursus Americanus, 616 
arctos, 616 
maritimus, 616 
Urus, 612 
Uvella, 32 
Varanus, 504 j 
Variation of species, 672 
Veliger stage of mollusks, 282, 
239, 248, 246 
Velum of rotifers, 176, 178 
Venus mercenaria, 229 
Vermes, characters of, 96 
classification of, 176 
Vertebra, 375 
Vertebrata, characters of, 369 
classification of, 680 
brain of, 372 
ear of, 385 
eye of, 385 
hair of, 383 
limbs of, 376 
notochord of, 373 
scales of, 383 
skeleton of, 875 
skull of, 377 
teeth of, 381 
Vertebrates, relations of ascidians. 
to, 386 
mollusks to, 221 
worms to, 157, 167 
Vespertilio subulatus, 591 
Vinegar worm, 128 
Viper, 499 
