655 



alveolate, 456 ; pectiuate, 456 ; pincer- 

 shapeil, 456 ; valvate, 456 ; I'orciiiulate, 

 433, 434, 456, 462 ; representatives in 

 Opliiuroidea, 492 ; in OphiothrLc frcuj- 

 Ui». 492 ; in Oph'whdus, 492, 493 ; of 

 Kchiiius acutus, 509 ; of E. csfi'!fiilus. 

 50t5 f., 507 ; tridactyle, 506, 509, 510 ; 

 gemniiform, 506, 509, 510 ; trifoliate, 

 50S, 509, 510 ; oi>liicephalous, 508, 509, 

 510 ; function of, 508 f. ; of Eudo- 

 ryclica, 532 ; of Cidaridae, 532 ; of 

 Ecliinotluiiiidae, 532, 535 ; of Centru- 

 stcphKHiis/iiiuiispiuosus, 532 ; ofEehina- 

 racJiiiiiix pannn, 544, 545 ; of Echino- 

 cardium cvrdatum, 550 ; absent in 

 Pelmatozca, 582 



Pedicellaster, 4'' 4 



Pediqpllasteridae, 456, 4'i'4 



I'djantha, 290 



Peganthidae, 296 



Pekelharing, 187 n., 234 n., 237 



Pdagia, 311, 312, 315, 316, 323; P. nodi- 

 U(ca,^\\; P. jae'-Za, 323 ; P.phosj)hora, 

 311, 323 



Pelagic, Foraniinifera, 61, 66, 69 ; Radio- 

 laria, 76 ; Dinoliagellates, 131 



Pelagiidae, 323 



Pdagohydra, 263, 21 J,. ; P. mirahili% 274 



Pelagohydridae, 274 



Pelagothuria, 568, 569, 572 ; P. natans, 

 572 



Pelagothiiriida, 572, 577, 578 



Pellicle, of Protozoa, 46 ; of Flagellates, 

 109 f., 113; of Nodiluca, 133; of 

 Ciliata, 139, 141, 142 ; of ColeiJs, 141. 

 152 ; of Dysteria, 153 ; of Vorficdla, 

 157 ; of Suctoria, 159 ; of tentacles of 

 Suctoria, 161 — see also Cuticle 



Pelmatozoa, 4^0, 579 f. ; phylogeny of, 

 621 



Pelomyxa, 51 ; P. palustris, 52 f. ; pepsin 

 in, 16 



Penard, on Heliozoa, 71 ; on Rhizopoda, 

 58 n. 



Peneroplis, 59, 66 ; jjylomes of, 64 



Peniagone, 572 



Pennaria, 272 



Pennariidae, 272 



Pennaiula, 361 ; P. grandis, 361 ; P. 

 murrayi, 359, 362 ; P. naresi, 362 ; P. 

 phos2)horea, 338, 361 



Pennatulacea, 333, 335, 337, 358, 358, 

 359, 363 f. 



Pentateros, 472 



Pentacerotidae, 457, 458, 459, 471 



Pentadiogon, 294 



Pentacrinidae, 588, 589, 591 f. 



Pentacrinoidea, 595 



Pentacrinus (Isocrinus), 591 f. ; P. asteria, 

 692 ; P. madearnnux, 593 



Pentagonaster, 471 ; P. japonicus, 472 



Pcntagonasteridae, 455, 4'^! 



Pentremites, 599 



Pepsin, 16 



Peptic, digestion, 16 ; juice in Cardiesium, 

 147 



Peptones, 15 



Perforate, Corals, 371 ; Foraniinifera, 5S L 



Pn-iholaster, 453, 463 



Peril irancliial spaces of Aster ias ruhens, 

 449 



Pcricolpa, 3JJ 



Peiidiniales, synonym of Dinotiagellataused 

 by Schiitt, 119, 132 



Pcridinium, IIU ; fossil, 132 ; P. divergens, 

 131 



Pciigonimus, 265, 266, 269 



Periliaemal spaces (or canals), of A sterias 

 rubens, 448 ; of OpInotJmx/ragiUs, 481, 

 488 ; of Edtinus esculentus, 524 ; of 

 Holothuria nigra, 566 



Peripatus, segmentation of, 32 n. 



Pcriphylla, 311, 314, 322 \ P. regina, 

 322 



Periphyllidae, 310, 322 



Periproct, of Ediinus esculentus, 504, 507, 

 512, 513, 534 ; of Endocyclica, 530, 

 534, 538 ; of Cidaridae, 530, 533, 534 ; 

 of Arbaciidae, 530 ; of Echinotluiriidae, 

 535 ; development of, in young Echinoid, 

 613 



Peripylaea ( = Spumellaria), 76 



Perisarc, 251, 263 



Perisiphonia, 277, 2S0 



Peristalsis of intestine of Holothuria nigra, 

 563 



Peristome, of Ciliata, 137 f. ; in fission, 

 147 ; of Peritricliaceae, 155 f. ; of 

 Vorticellidae, ]55 f., 157; of Asterias 

 rubens, 434 ; of Echinus esculentus, 

 505, 513, 514 ; of Asteroidea, 514 ; of 

 Cidaridae, 514, 530, 533 ; of Endocyclica 

 530 ; of Echinothuriidae, 535 ; of As- 

 thenosoma hystrix, 537 ; of Saleniidae, 

 537 ; of Arbaciidae, 538 ; of Diadema- 

 tidae, 538 : of Echinidae, 539 ; oi' Echino- 

 cardium cordcdum, 550 ; of Spatangoidea, 

 553 ; of Palaeostomatidae, 554 



Peristomial area, 139 ; of CaetiomwplM 

 aii<l Metopus, 154 ; o{ Bursar ia, 155 



Peristomial collar, 142, 156, 157 



Peristomial plate, of Ophiothrix fragilis, 

 483 ; of Endocyclica, 530 ; of Cidaridae, 

 530, 533 ; of Ecliinothuriidae, 530, 535 ; 

 of Saleniidae, 537 ; of Arbaciidae, 538 ; 

 of Echinus microtuberculalus, 540 



Peritoneum, of Asterias ndiens, 437 ; of 

 Holothuria nigra, 567 



Peritricliaceae, 138; pellicle, 141 ; myo- 

 nemes, 142 ; trichocysts, 143 ; contrac- 

 tile vacuole and reservoir, 145 ; pharynx, 

 vestibule, mode of feeding, 145 ; fission, 

 147 : conjugation, 151 ; peristomial 

 collar, 156, 157 



