Nephrie gland, 111 
Nerinea, 154 
Nerita, 150 
Neritina, 150 
Neritodomus, 150 
Neritopsis, 150 
Niso, 158 
Notarchus, 171 
Notobranchaea, 178 
Notomenia, 60 
Nuchal plate, 264 
Nucula, 255 
Nuculina, 256 
Nudibranchia, 174 
Nuttalochiton, 53 
Octopoda, 342 
Octopus, 348 
Ocythoé, 343 
Odontomaria, 147 
Odontoperna, 260 
Odostomia, 158 
Odostomiopsis, 168 
Oigopsida, 336 
Oleacina, 189 
Oliva, 165 
Olivella, 165 
Ommatostrephes, 388 
Omphalotropis, 152 
Oncidiella, 190 
Oncidiopsis, 156 
Oncidium, 190 
Oncospira, 150 
Oniscia, 157 
Onitochiton, 54 
Onychoteuthis, 339 
Oocorys, 157 
Opeas, 188 
Operculum, 71 
Ophidioceras, 333 
Ophileta, 147 
Opis, 264 
Opisthobranchia, 167 
Opisthopodium, 216 
Opisthoteuthis, 342 
Oppelta, 335 
Orpiella, 187 
Orthalicus, 188 
Orthoceras, 3832 
Orthoneura, 114 
Oscaniella, 174 
Oscantopsis, 174 
Oscanius, 174 
Ostracolethe, 187 
Ostraea, 263 
Ostraeacea, 263 
Otina, 184 
Otocardia, 1 
Otoconia, 119 
Otocrypt, 18 
Otocyst, 18 
INDEX 
Otoliths, 18, 119 
Ovula, 157 
Oxygyrus, 163 
Pachycardia, 267 
Pachyrisina, 267 
Palaeacma, 145 
Palaeoconcha, 256 
Palaeoctopus, 342 
Palio, 177 
Palliata, 1 
Paludina, 152 
Paludomus, 154 
Pandora, 276 
Paracephalophora, 66 
Puraclione, 173 
Parallelodon, 258 
Paramenia, 60 
Paramya, 273 
Parapodia, 69 
Pararhopalia, 60 
Parmacella, 187 
Parmarion, 187 
Patella, 145 
Patrocardiwmn, 261 
Pearls, 213 
Pecten, 262 
Pectinacea, 260 
Pectinibranchia, 151 
Pectinodonta, 145 
Pectunculus, 258 
Pedicularia, 157 
Pedipes, 184 
Pedum, 262 
Pelecypoda, 205 
Peltella, 188 
Peltoceras, 336 
Peraclis, 170 
Pergamidea, 262 
Pericardie glands, 18 
Pericardium, 12 
Periostracum, 4 
Periploma, 275 
Perisphinctes, 336 
Perna, 259 
Peronia, 190 
Persona, 157 
Petersia, 157 
Petricola, 270 
Phanerophthalmus, 169 
Phanerotinus, 147 
Phasianella, 150 
Philine, 169 
Philobrya, 258 
Philomycus, 187 
Phlebcedesis, 8 
Pholadella, 276 
Pholadidea, 275 
Pholadomya, 276 
Pholas, 275 
Phos, 164 
Photinula, 149 
Phragmoceras, 332 
Phragmoteuthis, 337 
Phyllaplysia, 171 
Phyllidia, 178 
Phyllirhoé, 175 
Phyllobranchus, 181 
Phylloceras, 385 
Phylloteuthis, 342 
Physa, 186 
Phythimya, 276 
Pileolus, 150 
Pilidium, 145 
Pinacoceras, 335 
Pinna, 264 
Pinnigena, 264 
Pinnoctopus, 348 
Pisania, 164 
Pisidium, 267 
Placiphorella, 58 
Placophoropsis, 58 
Placuna, 257 
Placunanomia, 257 
Plagiodon, 268 
Plagioptychus, 272 
Plakobranchus, 181 
Planaxis, 152 
Planktomya, 33 
Planorbis, 185 
Platyceras, 155 
Platychisma, 147 
Platydoris, 178 
Platymalakia, 66 
Platyodon, 273 
Platypoda, 157 
Plaxtiphora, 53 
Plectomya, 275 
Plectrophorus, 71 
Plesioteuthis, 342 
Pleural ganglion, 112, 201, 
234 
Pleurobranchaea, 174 
Pleurobranchomorpha, 173 
Pleurobranchus, 174 
Pleurocera, 154 
Pleurodonta, 187 
Pleuromya, 276 
Pleurophorus, 264 
Plewrophyllidia, 180 
Pleurotoma, 166 
Pleurotomaria, 146 
Plicatula, 262 
Pliodon, 268 
Plocamopherus, 177 
Plutonia, 186 
Pneumonoderma, 173 
Podocyst, 136 
Polycera, 177 
Polyconites, 272 
Polygyra, 187 
Polyplacophora, 41 
