Opishonephros, 299, 316 



Optic chiasma, 384, 386 



Optic cup, 383, 404 



Optic foramen, 129 



Optic lobe, 388 



Optic nerve (II), 386, 404 



Optic-orbital-round fissure, 49 



Optic pedicel, 1 19 



Optic stalk, 404 



Optic tracts, 386 



Optic vesicle, 383, 404 



Oral cavity, 253 



Oral division of mandibular (sensory-canal) 



line, 410 

 Oral funnel, hood, 5 

 Oral lamella, 14 

 Oral processes, 1 30 

 Orang, 292 



Orbit, 37, 46 I 



Orbital cartilage, 54, 80, 1 08, 1 2 1 , 1 3 1 

 Orbital fissure, 40, 53 

 Orbital process, palatoquadrate, 119 

 Orbital sinus, venous, 363 

 Orbitocapsular commissure, 122 

 Orbitonasal fissure, 51 

 Orbitonasal foramen, 49 

 Orbitonasal lamina, 108, 122 

 Orbitoparietal commissure, 131 

 Orbitosphenoid, 40, 46, 48, 49, 64, 71, 80, 



83, 106 

 Ordovician, 63, 135, 137, 229, 240, 444 

 Organ ofCorti, 408 

 Organogenesis, 194 

 Origin, mammals, 76 

 Origin of a muscle, 420 

 Origin, birds, 76 

 Origin, hair, 221 



Ormlhorhymhus, 22, 29, 44, 220, 254, 320, 383 

 arterial roots, 348 

 brain, 3S5 



chondrocranium, 55 

 digestive tract, 255 

 external appearance, 29, 29 

 head skeleton, 45, 45, 47 

 pectoral girdle, !73 

 Orobranchial area, 136 

 Orthodentine, 228 

 Onnkmna. scale, 235, 235, 240 

 Os incisivum, 36 

 Osmerus, reproductive system, female, 329, 



331 

 Ospiidae, 1 15 



Ossicles (malleus, incus, and stapes), 41 

 Ossicular cavity, 40 

 Ostariophyses, 410 

 Osteichthyes, 105, 117, 170, 192, 290,444 



sensory-canal system, 4J J 

 Osteoclasts, 229 

 Osteodentine, 228, 248 

 Osteoderms, 221, 226 



Osteolepis, Osteolepidae, 21, 33, 92, 113, 416 

 external appearance, 32 

 tooth structure, 249 

 Osteolepiforms (see also Osteolepididae, 

 Rhipidistia), 21, 192 

 head skeleton of, 92 

 Osteology, place of, 34 



Osteons, 228 



Osteostracan, Osteostraci, 19, 135, 168, 170, 

 409, 412 



endocranium of, 136 



head skeleton, 135, J36 

 Ostium, 299, 321, 325, 339 

 Otic capsules, 51, 53, 64, 107, 108, 112, 114, 



120, 129, 131, 198 

 Oticoccipital segment, endocranium, 61, 65, 



88,94, 125 

 Otic process of palatoquadrate, 119 

 Otic vesicle, 406 

 Otacratm, 88 

 Otocyst, 406 



Otolith (statocyst), unicellular, 11 

 Outer (terminal) sinus, 205 

 Outer shell membrane, 201 

 Oval, 284 

 Ovary, 320 

 Oviducts, 320 

 Oviparous, 21 1 



Ovocoel (gonocoel of ovary), 327 

 Ovoviviparous, 21 1 

 Ovum, 193 

 OWEN, 2, 3, 35, 383 

 Ox, 348 



Pnlaeodus, 246, 246, 444 

 Palaeogyrmus, 86, 87 

 Palaeoniscoids, 20, 105, 234, 415 



endocranium, 114 



external appearance, 32 



head skeleton of, 112, 113 



hyomandibula, 115 



vertebrae, 162, 163 

 Palaeozoic, 63 

 Palatal fenestra, 64 

 Palate, secondary, 46 

 Palatines, 39, 46, 64, 65, 82, 86, 106, 111 

 Palatine canal, 49 

 Palatine commissure, 131 

 Palatine foramen, 39 



Palatoquadrate, 64, 80, 106, 108, 119, 122, 

 125, 127 



ascending process of, 64 



complex, 65, 85 

 Paleocene, 62 

 Paleopallium, 388 

 Palingenesis (or paleogenesis), 3 

 Palito-hyomandibular foramen, 122 

 Pallial commissure, 383, 384, 388, 393 

 Pallial dentine, 228 

 Palmaris longus, 428, 433, 436 

 Pangolin, see Mams 

 Pancreas, 253, 256, 259, 264, 382 

 Pancreatic diverticulum, 256 

 Papilla, 291 



Papillary layer, of dermis, 218 

 Papillary muscles, 340 

 Papilla of Vater, 253 

 Parabasal canal, 64 

 Parabronchi, 281 

 Parabuccal rods, 131 



Parachordal cartilage, 53, 107, 120, 128, 131 

 Parachordal plate, 64 

 Paradidymis, 319 

 Parameles, 212 



Paranasal cartilages, 53, 54 

 Paraphyseal process, 122 

 Parapineal, see parietal eye 

 Parapophysis, 142, 145, 149, 158, 188 

 Parareptilia, 71 



Pamsemionolus, Para,semionotidae, J2, 33, 115 

 Paraseptal cartilage, 53 



Parasphenoid, 59, 64, 69, 80, 83, 85, 105, 

 107, 125 

 in mammal (opossum), 43, 44 

 Parasympathetic system, 387 

 Parathyroid, 380, 381 

 Paraventricular nucleus, 384 

 Parenchymal cells of pineal, 382 

 Parietal bone, 37, 49, 69, 76, 79, 82, 94, 96 

 Parietal eye (parapineal), 388, 405 

 Parietal foramen, 61, 65, 76, 85 



in actinopterygian, Moylhomasia, 1 14 

 Parietal nerve, 388 

 Parietal plates, 51, 53 

 Parietocapsular fissure, 51 

 PARKER, 3, 139, 370 

 Paroccipital process of opisthotic, 51, 53, 61, 



76 

 Paroophoron, 322 

 Parotid salivary gland, 387 

 Parovarial ovary, 329 

 Patella, 428 

 Pavo, 257 

 Pearl organs, 225 

 Pecten, 405 

 Pectineus muscle, 429 

 Pectoantibrachialis, 424 

 Pectoral fin, 23, 181 

 Pectoral girdle, 173, 174, 179 

 Pectoral limb, tetrapod. 171, 173, 177 



origin of, 182 

 Pectoralis, 432, 436 

 major, 424 

 minor, 424 

 pars humeralis, 424 

 pars pectoantibrachialis anterior, 424 

 pars pectoantibrachialis posterior, 424 

 pars xiphihumeralis, 424 

 Pedeles, 323 

 Peduncle, 385 



Pellucid area, see area pellucida 

 Pelobales, 223 

 Pelvic cartilage, 182 

 Pelvic fin, 23, 180, 182, 183 

 Pelvic girdle, 141, 143, 145, 149, 177. 182, 



183 

 Pelvic hmb, 171, 175, 178 

 Pelvis, 147, 291 



Pelycosaurs, 89, 151, 174, 176, 343,448 

 Penetration path, 199 

 Penguin, external appearance, 29 

 Penis, 259, 318, 320, 324 



turtle and crocodile, 324 

 Pennsylvanian, 63, 85, 86, 88, 151, 445 

 PentadactI, limb, 180 

 Perametes, 320, 322, 323 

 Perca, Perch, 20, 106, 181 

 external anatomy, 25, 25 

 fin base and scapulocoracoid area, 185 

 skin, 225 

 Periblast cells, 201, 203, 205, 207 



INDEX 



471 



