INDEX 



Hsemocoele, 608 : Digestive system, 

 608, 609 : Renal organs, 609 : Heart, 

 609 : Respiration, 609, 610 : Ner- 

 vous system, 610, 611 : Organs of 

 special sense, 611 : Reproductive 

 organs, 611 : Development, (512, 613, 

 614, 615 : Systematic position, 621 



Periplaneta orientals, 603, 604, 605 



Periproct, 386* 



Perisarc, 131, 132, 133 



Peristaltic movements, 37*, 434 



Peristome, 94, 97, 98, 185*, 373*, 386* 



Peristomium, 430*, 444, 460 



Peritoneum, 445* 



teritrichous ciliation, 94*, 98 



Peri visceral cavity, 432* 



Periwinkles, 663 



Perlidce, 618 



Peromedusse, 179 



Per-radius, 139* 



Petaloid ambulacra, 413 



Petasus, 154 



Petrarca, 551, 565 



Phacellse, 171* 



Phacops fecundus, 589 



Phseodium, 62, 64 



Phalangida, 645*, 649, 651, 653 



Phanerocephala, 454*, 456, 464, 472, 

 476 



Pharynx See Digestive system 



Phasmidce, 621, 637 



Pheronema carpenteri, 122, 124 



Philodina, 321, 324, 327 



Pholas, 678, 682, 692 



Phoronida, 333, 348, 353 



Phoronis, 348, 349, 350, 351, 352 



Phragmacone, 772* 



Phragmoceras, 780 



Phreatoicus, 554 



Phronima, 571 



Phrynus, 647 



Phylactolaemata, 341*, 342, 343, 344, 

 345, 346 



Phyllocarida, 552*, 566, 567, 579, 581, 

 586, 587, 588 



Phyllodoce paretti, 468 



Phyllosoma, 585 



Phylogeny, 8* 



Phylum, 5*, 43* 



Physalia, 163, 164 



Physiology, 9* 



Phytoflagellata, 75 



Pieris, 620 



Pigment, 70, 120 



Pilema, 181 



Pilidium, 290 



Pill-bug, 572 



Pinacocytes, 120* 



Pinna, 678, 685 



Pinnotheres. 586 



Pinnules, 398* 



Pionosyllis elegans, 472 



Piscicola, 504, 510 



Placenta, 597 



Placophora, 694*, 697, 698, 699, 701, 

 702 



PLANABIA, 233 : General features, 233, 

 234, 236 : Digestive system, 233, 

 234: Water vessels, 234, 235: 

 Nervous system, 234, 235 : Re- 

 productive system, 235, 236 : Syste- 

 matic position, 249 



PlanaridcB, 249 



Plankton, 8* 



Planocera, 269, 271 



Planorbis, 241 



Planorbulina, 54 



Plant lice, 619, 632 



Planula, 140*, 153, 172, 173, 190 



Plasma, of blood, 30 



Plasmodium, 31*, 68, 69 



Plasmosome, 18* 



Plastin, 17*, 18 



Platyctenea, 218*, 221, 222, 223 



Platyhelminthes, 233, 248* : Ex- 

 amples, 233, 236, 243 : Systematic 

 position, 249 : General external 

 features, 250 : Integument and 

 muscular layers, 257, 259 : Paren- 

 chyma, 259 : Alimentary systems, 



260, 261, 262 : Nervous system, 



261, 262, 263 : Water-vascular 

 system, 263, 264 : Reproductive 

 organs, 264, 265, 266, 267 : De- 

 velopment, 268, 269. 270, 271, 272, 

 273, 274, 275, 276, 277, 278: 

 Asexual reproduction, 278 : Dis- 

 tribution, occurrence, and relation- 

 ships, 279, 283 : Appendix, 284 



Platypoda. 714*, 715 



Pleopod, 530* 



Pleurobrachia, 208 



Pleurobrachiidce, 218 



Pleurobranchia, 536, 537* 



Pleuron, 528* 



PleurophyUidia, 723 



Ploitna, 322*, 323 



Plumatella, 341, 342 



Plumularia, 149 



Pluteus, 392, 403, 422, 423 



Pneumatophore, 160, 161* 



Podia, 370*, 413 



Podical plates, 606* 



Podobranchia, 536, 537* 



Podomere, 514* 



Podophrya, 101, 102 



Podura, 616 



Polar body, 21*, 22 



Polar plates, 213* 



Polian vesicles, 376, 377*, 391, 394, 417 



Pollicipes, 565 



Polyarthra, 322, 323, 331 



Polycelis, 251 



Polychseta, 454*, 460, 461, 463, 466, 467, 



468, 469, 470, 471, 472, 474, 475, 



477 



