Neurankylus eximius, 94 
Niobrara epoch, turtles of, 36 
niobrarensis (Stylemys), 437 
(Testudo), 398, 437 
nodosus (Taphrosphys), 105, 122 
Notomorpha, 225, 226, 269 
garmanii, 269 
gravis, 269 
testudinea, 303 
Number of species, 2 
obscura (Compsemys), 235 
obscurus (Emys), 235 
obtusa (Testudo), 398, 458 
obtusus (Eupachemys), 458 
octonarius (Hadrianus), 376 
ocyrrhoé (Echmatemys), 298, 329 
cedemia (Anostira), 479 
cedemius (Plastomenus), 467, 479 
ogmius (Basilemys), 226 
(Compsemys), 226 
oregonensis (Stylemys), 392 
(Testudo), 392 
Origin of turtles, 28 
ornata (Anosteira), 279 
(Anostira), 279 
ornatus (Chelone), 210 
(Glyptops), 47 
(Peritresius), 210 
orthopygia (Testudo), 398, 438 
(Xerobates), 438 
osborniana (Testudo), 398, 422 
Osteology of turtles, 2 
Osteopygis, 127 
borealis, 128, 141 
chelydrinus, 128, 136 
emarginatus, 128, 129 
erosus, 128, 138 
gibbi, 128, 132 
platylomus, 128, 129, 146 
ponderosa, 152 
repandus, 150 
robustus, 128, 134 
sopitus, 128, 141, 149 
oweni (Emys), 386 
(Testudo), 386 
oxysternum (Agomphus), 249, 256 
(Amphiemys), 256 
pachylomus (Emys), 301, 302 
Pachyrhynchus, 160 
Paleotheca, 287, 343 
polycypha, 343 
terrestris, 344 
paludosa (Hoplochelys), 266 
pansa (Testudo), 398, 420 
parva (Emys), 246 
parviscutatus (Chelone), 220 
parviscutum (Chelone), 220 
(Puppigerus), 220 
parvitecta (Chelone), 220 
(Chelonia), 220 
parvitectus (Puppigerus), 220 
pectorale (Pleurosternum), 254 
pectoralis (Adocus), 254 
(Agomphus), 249, 254 
Pelvis, structure of, 7, 9, 12, 14, 16, 21 
pennata (Amyda), 511, 514 
pennatus (Trionyx), 514 
peragrans (Testudo), 398, 412 
percrassa (Clemmys), 290, 294 
Peritresius, 209 
ornatus, 122, 210 
pertenuis (Testudo), 398, 454 
pervicax (Glyptops), 54 
petrolei (Emys), 352 
(Trachemys), 348, 352 
petrosus (Adocus), 250 
INDEX. 
petrosus (Agomphus), 249, 250 
(Emys), 250 
Phylogeny of turtles, 27, 28 
Pierre epoch, turtles of, 36 
planimentum (Chelone), 154 
Plastomenide, 466 
Plastomenus, 466 
acupictus, 467, 470 
catenatus, 467, 470 
coalescens, 488 
communis, 467, 473, 451 
corrugatus, 467, 473 
costatus, 467 
fractus, 467, 472 
insignis, 467, 469 
lachrymalis, 467, 472 
leptomitus, 467, 470 
molopinus, 467, 481 
multifoveatus, 470, 474 
cedemius, 467, 479 
punctulatus, 467, 468 
serialis, 537 
tantillus, 467, 478 
thomasi, 467, 474, 476, 537 
trionychoides, 541 : 
visendus, 467, 476 
Platemys sulcatus, 104, 106 
Platychelys, 59 
platylomus (Osteopygis), 128, 129, 146 
platyops (Euclastes), 162 
(Lytoloma), 160, 162 
(Rhetechelys), 162 
Platypeltis, 483, 536 
amnicola, 536, 540 
antiqua, 536, 537 
extensa, 537) 545 
ferox, 11, 537) 548 
heteroglypta, 5375 543 
leucopotamica, 537, 546 
postera, 537) 545 
serialis, 536, 537 
trepida, 536, 541 
trionychoides, §37, 541 
Plesiochelyide, 45 
Plesiochelys belviderensis, 53 
Plesiosauria, 30 
Pleurodira, 12, 19, 20, 25, 34, 43, 102 
Pleurosternida, 45 
Pleurosternon, 46 
Pleurosternum pectorale, 254 
plicatulus (Compsemys), 47 
(Glyptops), 47 
polemicus (Lembonax), 212 
polycypha (Emys), 343 
(Palzotheca), 343 
Polythorax, 58, 100 
missuriensis, 100 
ponderosa (Baéna), 271 
(Catapleura), 152 
(Osteopygis), 152 
Porthochelys, 180 
brown, 182 
laticeps, 180 
postera (Platypeltis), 537, 545 
| potens (Protostega), 189, 198 
| pravus (Adocus), 236, 242, 246 
(Emys), 246 
Preneural bone, 57 
princeps (Prochonias), 114 
(Taphrosphys), 114 
prisca (Amyda), 511, 512 
priscus (Trionyx), 512 
Probaena, 58 
sculpta, 58 
procax (Toxochelys), 168, 176 
Prochonias, 104 
553 
