528 



MOLLUSCA — BRACHIOPOD A 



Patelliform shell in various genera, 19 



Paterina, 509, 510, 511 



Patinella, radula, 227 



Patula, 297, 298, 318-338, 340, Ul 



Paxillus, 41S 



Pearl oysters, 100 



Pecten, 446, 450, 450 ; organs of touch, 

 178 ; ocelli, 191 ; flight, 192 ; nervous 

 system, 206 ; genital orifice, 242 ; 

 ligament, 271 



Pectinodonta, 405 ; radula, 227 



Pectunculus, 4-48 



Pedicularia, 75, 419 ; radula, 224 



Pedinogyra, 319, 322, 442 



Pedipes, 18, 199, 439, 439 



Pedum, 450 



Pelagic MoUusca, 360 



Pelecypoda, 7, 445 ; development, 145 ; 

 generative organs, 145 ; branchiae, 

 166-169 ; organs of touch, 178 ; eyes, 

 189 f.; foot, 201 ; nervous system, 205 



Pella, 333 



Pellicula, 352, 442 



Peltoceras, 399 



Pentadactylus, 4^3 



Peraclis, 436 



Pereiraea, 4I8 



Perideris, 328-330, 443 



Periodicity in breeding, 129 



Periophthalmus, 187 



Periostracum, 275 



Periploma, 459 



Perisphinctes, 399 



Perissodonta, 4I8 



Perissolax, 424 



Peristernia, 4^4 



Perna, 449 ; ligament, 271 



Pernostrea, 449 



Peronaeus, 358, 442 



Peronia, 443 



Perrieria, 319, 442 



Perrinia, 4O8 



Persicula, 425 



Persona { = Distortio) , 420 



Petenia, 353, 440 



Petersia, 420 



Petraeus, 295, 331, 442 



Petricola, 454 



Phacellopleura, 403 



Phanerophthalmus, 430 



Phaneta, 4O8 



Phania, 312, 441 



Pharella, 457 



Pharus, 457 



Pharynx, 210 



Phasianella, 409 



Phasis, 333 



Phenomena of distribution, 362 



Philine, 245, 428, 430; protective 

 coloration, 73 ; radula, 229, 230 



Philomycus, 245, 318, 440 



Philonexis, 138 



Philopotamis, 304, 417 



Phoenicobius, 315, 44I 



Pholadacea, 457 



Pholadidea, 457 



Pholadomya, 459 



Pholas, 245, 274, 447, 457 ; in fresh 



water, 15 

 Phos, 424 

 Photinula, 4O8 

 Phragmophora, 386 

 PhylUdia, 434 ; breathing organs, 159 

 Phyllirrhoe, 360, 428, 433 

 Phyllobranchus, 432 

 Phylloceras, 398, 398 ; suture, 396 

 Phylloteuthis, 390 

 Physa, 439 ; aestivating out of water, 



27 ; spinning threads, 29 ; sudden 



appearance, 46 ; osphradium, 195 ; 



nervous system, 205 ; radula, 235 ; 



P. hypnorum, 23, 27 

 Pileolus, 410 

 Pileopsis, 76 

 Piloceras, 394 

 Pinaxia, 423 

 Pineria, 442 

 Pinna, 449 ; shell, 254 

 Pinnoctopus, 385 

 Pinnothet'es, 62 

 Pinoceras, 398 

 Pirena, 417 

 Pirenella, 4I6 

 Piropsis, 424 

 Pirula — see Pyrula 

 Pisania, 424 

 Pisidium, 453 ; smell, 195 ; ova, 146 ; 



P. pusillum, distribution, 282 

 Pitys, 327 



Placohranchus, 482 

 Placostylus, 322, 323-325, 359, 442', 



radula, 233 

 Placmia, 448; P. placenta used for 



windows, 101 

 Placunanomia, 448 

 Placunopsis, 448 

 Plagioptycha, 347-351, 441 

 Plagioptychus, 456 

 Planaxis, 417 



Planispira, 311, 312, 319, 441 

 Planorbis, 27, 247, 439 ; monstrosity, 



93 ; eye, 181 ; P. alhus, distribution, 



282 

 Platyceras, 76, 412 

 Platydoris, 434 

 Platypoda, 4II 

 Platyschisma, 413 

 Plaxiphora, 403 

 Plecochilus, 442 

 Plecotrema, 439 

 Plectambonites, 505 

 Plectomi/a, 459 



Plectopylis, 303, 305, 314, 316; aper- 

 ture, 63 



\ 



