Posterior air sac, 281 

 Posterior auricular artery. 354 



vein. 360, 361 

 Posterior basicapsular commissure. 131 

 Posterior capsular commissure, 107 

 Posterior cardinal vein, postcardinal, 314, 



339, 368 

 Posterior commissure, 393, 405 

 Posterior facial vein. 361 

 Posterior hepatic vein, 376 

 Posterior lacerate fossa. 40 

 Posterior lateral cartilage, 130 

 Posterior lateral field. 136 

 Posterior ma.xillary process, 122 

 Posterior pelvic clasper, 24 

 Posterior pit line, 410 

 Posterior tectal cartilage, 130 

 Posterior tectum, 122 

 Posterior vena cava, 340, 368, 369 

 Posterior vestibular center, 121 

 Postfrontal, 61 

 Postglenoid process, 37 

 Postminimus, 178 

 Postnasal. 127 



Postorbital bone. 61, 76, 85, 105 

 Postorbital cartilage, 122 

 Postorbital process, 119, 125 

 Postotic segments. 293 

 Postparietal, 36, 37, 44. 85, 94 

 Post pectorals, 181 

 Postspiracular, 94 

 Postsuborbital, 127 

 Posttemporal. 179, 181. 184 

 Posttemporal canal. 76 

 Posttemporal fossa, 46, 49, 7 1 

 Postventrolateral plate, 184 

 Postzygapoph\-ses, 141, 145 

 Prearticular, 76, 83. 85 



anterior process of malleus, 41 

 Preatlas, 145, 147 

 Precerebral fossa, 119, 122 

 Prechordal plate, 198, 203, 207 

 Predentine, 245 

 Prefacial commissure, 110 

 Prefrontal, 61, 76, 82, 84, 85 

 Premaxilla, 39, 43, 45, 64, 71, 83, 85, 106, 

 114 



origin in teleost, 1 II 



palatal processes, 39 



prenasai processes, 46 

 Premolar teeth, 39, 251 

 Preoccipital arches, 64 

 Preoral pit, 196 

 Preopercular canal groove, 86 

 Preopercular sensory canal, 106, 410 

 Preopercle, 96, 106, 127 



in ichthyostegid, 88 

 Preoptic pillar, 80, 108, 122, 131 

 Preoptic recess, 384 

 Preorbital cartilage, 122 

 Preorbital plate. 119 

 Preotic coelomic pouches, 198 

 Preparaphysis, 388, 391 

 Prepollex, 171, 178 

 Presacral, vertebrae, 141, 148, 151 

 Presphenoid, 40, 58 

 Prespiracular cartilages, 122 



Primary centnun, 144 



Primar\- osteon systems. 228 



Primates, 22. 254. 291, 292 



Primitive features. 442 



Primitive (Hensens) node, 203 



Primitive mammal, urogenital system, 323 



Primitive node, 205, 207, 208 



Primitive pit, 203, 207, 208 



Primitive streak, 203, 207. 208 



Primitive stylomastoid foramen. 49, 51 



Primitive tetrapod, urogenital system, 323 



Pnsliophoms, 334 



Pnsliurus. 276, 286, 310, 31 1, J/2 



Proamnion, 205, 372 



Procartilage, 149 



Processus alaris, 51 



Processus recessus, 51 



Processus vaginalis, 319 



Procoelous vertebra, 145. 148. 150. 153 



Procoracoid, 171, 173 



plates, 177 

 Proctodeum, 201. 257, 324 

 Prodentine, 230 

 Progonalis. 326 

 Prokinetic skull, in bird, 76 

 Pronator quadratus, 433, 436 

 Pronator teres, 428, 433 

 Pronephric and mesonephric rudiments in 



human, 293 

 Pronephric blastema, human, 293 

 Pronephric crests, 300, 314 

 Pronephric duct, see nephric duct 

 Pronephric fossa, 318 

 Pronephros, 293, 294, 297, 3/3. 316 

 Pronucleus. 194 

 Prootic bone. 83, 106. 107 

 Prootic foramen. 1 22 

 Prootic process, 108 

 Proprioceptive fibers, 386 

 Propterygium, 181, 183 

 Proscapulohumeralis anterior, 432 

 Prosencephalon, 383 

 Prosencoel, 383 

 Prostate gland, 318 

 Prostatic utriculus, 319 

 Protandrous hermaphrodite, 337 

 Protandry, 337 

 Proterozoic, 63 

 Promts. 406 

 Protochordates, 5, 291 



embryological features compared with 

 vertebrate, 215 



relation to chordates, 16 

 Protocercal tail, 26, 169, 169 

 Protocoel. 12. 13 

 Protoheterocercal tail, 170 

 Protobatrachus, 85 



Prolopterus, 21, 99. 104, 156, 179, 180, 224, 

 239, 240, 264, 266, 279, 283. 287, 288, 

 304, 327, 344, 345, 350, 357, 365, 370, 

 381,385,404,416, 422 



aortic arches, 350, 351 



brain. 391, 392 



digestive tract, 265 



external appearance, 26, 27 



heart, 344 



larva, 2J4 



ovary, 329 



pectoral girdle, 180 



pelvic girdle, 183 



sensory-canal system, 417 



skin, 225 



urogenital system, 328 

 Proto-rhachitomous, 192 

 Frotosome, 12, 13, 14 



nene plexus, 14 

 Prototheria (Monotremata), 43 

 Prototrichs. 217, 221, 223, 225, 226 

 Protractor muscles of rasping organ, 133 

 Proximal centrale, 173 

 Pseudemys, 259 

 Pseudobranch (mandibular hemibranch). 



287, 289. 288, 288 

 Pseudohypophyseal fenestra or sellar fenes- 

 tra, 109 

 Pseudopodial extensions, 377 

 Psoas major, 430 

 Psoas minor, 430 



Pleraspis, Pteraspids, 19,50, 31, 134, 137, 168 

 Ptenchlhodei, pectoral fin, 190 

 Pterobranchs, Pterobranchia, 12, 14, 16, 19 

 Plmmsculus, 20, 32, 113, 162, 415 

 Puroplax, 177, 177, 178 

 Pterotic, 94, 106 



Pterygoid bone, 39, 43, 46, 64, 65, 69, 76, 

 80, 82, 85, 106 



ossification centers. 59 



subdivided, 60, 76 

 Pterygoid canal, 48, 49 

 Pterygoid cartilage, 51 

 Pterygoid process of palatoquadrate, 64 

 Pterylae, 222 

 Plychodera, 12, 19 

 Pubic process, 180 

 Pubis, 172, 176, 182 

 Pulmocutaneous arch, 343 

 PuUnonary arteries, 280, 284 



channels of truncus arteriosus, 339 

 Pulmonary vein, 280 

 Pulp cavity, 229, 243 

 Purkinje fibers, 340 

 Pymmpu. dermal bone, 229, 230 

 Pygostyle, 149 

 Pyloric gland, 1 1 

 Pyloric region, stomach, 264 

 Pyloric valve, 253, 256, 264 

 Pyniformis, 428 

 Pyramidalis, 422 



Quaternary, 62 



Quadrate bone, 37, 64, 69. 76, 83, 85, 125, 

 127 



as incus, 41 

 Quadrate cartilage, 53 

 Quadratus femoris, 428 

 Quadratus muscle of eye, bird, 422 

 Quadratojugal, 65, 76, 83, 85 



based to quadrate, 79, 1 1 1 



origin of, teleost, 111 



Rabbit (Lepus), 253, 403, 432 

 brachial plexus, 434 

 brain, 385 



INDEX • 473 



