Ophiacantha. 285 

 Ophiactis. 285 

 Ophiocoma (132) 

 OphiophoUs. 285 

 Ophioscole.x. 285 

 Ophiuroidea, 284 

 Ophlituspongia. 62 

 "Opisthobranchs," 177, 182 



Ophiothrix. 285 (131) 

 Opisthorchis. 1 25 * 

 Opossum shrimps, 235 

 Orb-weaver, 226*, 244* 

 Orchestia, 235 

 Oreaster, 278 

 Organelle, 21 

 Organ-pipe coral, 101 



Oriental sore, 27 

 Ormers, 178 

 Osilinus. 182* 

 Ostracoda, 232, 233* 

 Oslraea. 188 

 Oxylricha. 54 

 Oyster drills, 177, 181 

 Oysters, 188 



P 



Pagiinis (104) 

 Palaemonetes, 237 (92) 

 Paleonemerteans, 132 

 Palirmnis, 237, 239* 

 Palolo worm, 202 

 Panope, 190 

 Panuliriis, 237 

 Paper nautilus. 199 

 Paracenlrotiis, 283 

 Paracyamus, 235 

 Paragorgia. 101 

 Paramecium, 16*, 18*, 19, 20, 



21, 51 

 Paranemertes, 132 

 Parapodia, 201 

 Parasitic, 20 

 Parazoa, 15, 57 

 Parchment worm, 203, 204* 

 Patella, 180* 

 Patiria, 278 (126) 

 Peach ia. 105 

 Peanut worms, 156* 

 Pearl, 186 

 Pearl oysters, 188 

 Pecten, 186 (42), (43) 

 Pectinatella. 151*, 152* 

 Pedicellariae, 276 

 Pedipalpi, 248 

 Pedipalps, 226 

 Pelagia. 80 

 Pelecypoda, 184 

 Pelomyxa, 29 

 Pen shells, 1 87 

 Peneus, 236 

 Pennatida. 103 

 Pennatulaceans, 102 

 Peranema, 25* 

 Peridinium, 24 



Periostracum, 185 

 Peripatoides, 228 

 Peripatopsis, 228 

 Peripatus, 211* (88) 

 Periphylla. 80 

 Peritrichs, 54 

 Periwinkle, 180, 183 (56) 

 Petaloids, 283 

 Phalangida, 249 

 Phallusia (10) 

 Phanerozonia, 277 

 Phantom bottom, 198, 231 

 Phascolosoma, 156* 

 Pheroneina, 61 

 Philodina. 138 

 Phoronida, 15, 149* 

 Phoronis. 149 

 Phoronopsis, 1 49 

 Photoreceptor, 21 

 Pbronima, 235 

 Phylactolaemata, 152 

 Phyllangia (26) 

 Phyllopoda. 229* 

 P/ijjfl, 182 

 Physalia. 75 (8) 

 Physophora. 75. 76 

 Phytomastigina, 22 

 Phytomonads, 25 

 Phytomonas, 11 

 Piddocks, 190 



"Pill bugs," 234, 236* (89) 

 Pisastenll9 (118-122) 

 Piscicola, 225 

 Pismo clam, 189 

 Pistol shrimps, 237 

 Placohdella. 225 

 Planarians. 1 19, 121 

 Planorbis, 182 



Planula, 70. 97. 133 



Plasmodium. 50 



Platyhelminthes, 15, 119 



Platynereis. 202 



Pleurohrachia, 116* 



Pleuroploca. ill 



Plumatella, 152 



Plumularia, 70* 



Podocoryne. 13 



Pogonophora, 15, 148 



Poison. 23. 68, 177, 273 



Polinices. 179, 183* (55) 



Polychaeta, 201 



Polyclads, 123 



Poly gold ills, 204 



Polymastia (3) 



Polymastiginids, 27 



Poly orchis (6) 



Polyplacophora, 160 



Polyps, 68, 70 



Polystoma. 125 



Pond snails, 182 



Poulohdella. 225 



Porcellio, 234 



Porifera, 15 



Porites. Ill (25) 



Portuguese man-of-war, 69, 75 



(8)^ 

 Poterion, 62 

 Prawns, 236 (92) 

 Precious coral, 102 

 Priapulida, 15, 141* 

 Priapuhts. 141 

 Proak's, 139 

 Proboscis worm, 129 

 Procamharus (93) 

 Procerodes. 123 

 Procotyla, 123 



300 



