Manus, 26; crocodile, 265; dog, 408, =413=; duck, 323; frog, 164; mammalia, 503; newt, 147; Perissodactyles, =508=; turtle, 233 Marginal plate, turtle 216; -- ray, 131; -- shield, turtle, 214 Marmoset, _49_, 372 f. Marmot, frontals, 476 Marsipobranchii, _31_, _53_; spinal column, 56 Marsupial bones, 513 Marsupial mole, 43; see _Notoryctes_ Marsupialia, _43_; arm bones, 499; auditory ossicles, 486; cervical vertebrae, 443; caudal vertebrae, 453; general characters, 349; manus, 504; pectoral girdle, 494; pelvis, 513; pes, 521; ribs, 491; sacral vertebrae, 451; skull, 456; teeth, 422; thigh and shin, 517; thoraco-lumbar vertebrae, 447 _Mastodon_, _47_, _365_; teeth, 434 _Mastodonsaurus_, _35_, _136_; pelvis, 187 Mastoid portion of periotic, dog, 391 Maxilla, 22; cod, 98; crocodile, 254; dog, 397; duck, 318; frog, 159; newt, 144; turtle, 229 Maxillo-mandibular arch, 21 Maxillo-palatine, duck, 318 Maxillo-turbinal, dog, 395 Meatus, external auditory --, crocodile, 250; dog, 393; turtle, 228; internal auditory --, crocodile, 251; dog, 392, 400; turtle, 228 Meckel's cartilage, 22; cod, 100; dogfish, 77; salmon, 94 Median ethmoid, 21; cod, 98; Gymnophiona, 179; salmon, 91; -- fin, Amphibia, 52; cod, 86; dogfish, 79 Megachiroptera, _49_; general characters, 371 _Megalobatrachus_, _35_, _135_; carpus, 186; skull, 175 Megalosauridae, _38_ _Megalosaurus_, _38_, _208_ _Megapodius_, spur, 330 _Megaptera_, _44_, _357_ Megatheriidae, _44_, 352; humerus, 501; leg bones, 517; pelvis, 513; sacrum, 452; teeth, 424; thoraco-lumbar vertebrae, 447 _Megatherium_, _44_; femur, 517; manus, 505; pectoral girdle, 495; pes, 522; skull, 458 Megistanes, _40_, _299_ Membranous cranium, 17 Menobranchidae, _35_ _Menobranchus_, _35_, _135_; carpus, 185; pes, 188; skull, 174; teeth, 169 _Menopoma_, _35_; see _Cryptobranchus_ Mento-meckelian, 22; frog, 161; reptiles, 284 Merganser, _41_; beak, 329 _Mergus_, _41_ Merrythought, duck, 322 Mesethmoid, 20; dog, 390; duck, 317 _Mesoplodon_, _44_; teeth, 427 Mesopterygium, 79 Mesosauridae, _37_ _Mesosaurus_, _37_ Mesosternum, dog, 404 Metacarpal quill, duck, 303 Metacarpo-digital, duck, 303 Metacarpus, 26; see Manus Metacromion, hares and rabbits, 497 Meta-pterygium, 79 Metatarsus 26; see Pes Metatheria, _43_; general characters, 349