INDEX 



687 



tion of, in Annelida, 321 ; in Cerebmtulus 

 lacteus, 120 ; in DentaKum, 328 ; in Dreis- 

 sensia, 337 ; in adult Entoprocta, 386 ; in 

 Echiuroidea, 163 ; in Paludina, 310 ; in 

 Patella, 293, 297 ; in Polygordius, 134 ; 

 in Sipunculus, 380 



Protozoa, 20, 30 



Protozoaea larva of Euphausia, 203 ; of 

 Penaeus, 203 



Pseudozoaea stage in development of Stomato- 

 poda, 218 



Pulmouata, 291. 320 



Pupa of Cirripedia, 202 ; of Donacia, 260 ; 

 of Galerucettavlmi, 268 ; of Holothuroidea, 

 585 ; of Sacculina, 202 ; of Synapta 

 digitata, 538 



Pupal phase of development, definition of, 

 28 ; interpretation of, 656 



Purpura, 320 



Pyloric caeca, formation of, in Asterias, 

 471 ; in Asterina gibbosa, 477 



Pyloric gland, formation of, in Ciona in- 

 tbstinalis, 625 



Pyloric sac, formation of, in Asterias, 471 



Pyrosoma,637, 639 ; development of, 632-635 



Quadrant of egg, definition of, 106 

 Quartettes of micromeres, definition of, 106 ; 

 formation of, in segmenting egg of Patella, 

 293-295 ; in segmenting egg of Planocera, 

 106 ; in segmenting egg of Polygordius, 

 133-139 



Radial canals of medusa of Tubularia, 58 

 Radial cells in embryo of Polyyordius, 1 35 

 Radial nerve-cords, formation of, in Ophio- 



th rix frag il is, 498 

 Radial perihaemal canals, formation of, in 



Asterina gibbosa, 475 ; in Echinus escu- 



lentus, 515 ; in Ophiothrix fragilis, 494, 



495 

 Radial plates, formation of, in Ampliiii.ru 



sqii.nmata, 499 ; in Asterina gibbosa, 479 

 Radial shields, formation of, in Amphiura 



squamata, 499 

 Radial water -vascular canals, formation of, 



in Antedon rosacea, 549, 556 ; in Asterias, 



471 ; in (Jucumaria planci, 542; in Ophio- 

 thrix fragilis, 492 ; in Synapta digitata, 



533, 539 

 Radiating muscles, formation of, in Poly- 



rjordius appendiculatus, 150 

 Radius of embryo of Polygordius, 135 

 Radula-sac, formation of, in Loligo, 358, 



363 ; in Paludina, 315 ; in Patella, 301 

 Rat, development of spermatozoa of, 7 

 Rathkea, medusa of, 59 

 Recapitulation theory of development, 20- 



25, 649 ; presuppositions of, 220 

 Rectum, formation of, in Asterias, 471 ; in 



Asterina gibbosa, 478 ; in embryo of 



Pedicellina, 400 

 Recurrent coil of intestine, formation of. in 



Echinus esculentus, 520 



Reducing division, definition of, 6 



Regeneration of eye in Shrimps, 286 



Renilla reni/ornis, development of, 87 ; 

 formation of skeleton of, 88 



Reno - pericardial canal, formation of, in 

 Dreissensia, 346 ; in Loligo, 362 ; in 

 Paludina, 314 



Retinula of compound eye, formation of, in 

 Astacus, 189; inDytiscus, 276; inLimultis, 

 237 



Retraction of polar- lobe in egg of Dental ium, 

 326 



Retractor muscles of foot, formation of, in 

 JJreissensia, 342 ; of funnel, in Loligo, 

 361 ; in larva of Polygordius appendicu- 

 latus, 148 



Reversion, process of, in development of 

 Agelena, 227 ; in development of Donacia, 

 259 ; in development of Peripla neta, 260 



Rhabdites of Yungia, 115 



Rhabditis larva of A scar is megalocephala, 

 447 ; of Nematoda, 454 



RhabdoQoela, 102, 115 



Rhabdocoelida, 102 



Rhabdome, formation of, in eye of Agelena, 

 233, 234 ; in compound eye of Astacus, 

 189 ; in compound eye of Dytiscus, 276 



Rhagon of Oscarella, 44 



Rhizocrinus, 559, 560 



Rhyncobdellidae, 128, 161, 284 



Ribs of Beroe, formation of. 92 



Right anterior coelom of larva of A ste riits, 



467 ; of larva of Echinus esculentus, 509 ; 

 of larva of Ophiothrix fragilis, 490 



Right hydrocoele, development of, in larva 

 of Asterias, 466 ; in larva of Asterina 

 gibbosa, 474 ; in larvae of Echinus escu- 

 lentus, and Echinus miliaris, 528 ; in 

 larva of Ophiothrix fragilis, 491 



Right madreporic pore in larva of Asterias, 

 465 



Right posterior coelom of embryo of Antedon 

 rosacea, 547 ; of larva of Asterias, 467, 



468 ; of larva of Echinus esculentus, 509 ; 

 of larva of Ophiothrix fragilis, 490 



Right ventral horn of left posterior coelom 

 in larva of Asterias, 468 ; in larva of 

 Asterina gibbosa, 474 ; in larva of Echinus 

 esculentus, 514 ; in larva of Ophiothrix 

 fragilis, 494 



Ring muscles of larva of Polygordius ap- 

 pendiculatus, 148 



Ring-sinus, formation of, of larva of Amelia, 

 71 



Ripe ovum, definition of, 9 



Rosette-cells in embryo of Patella, 294 ; 

 formation of, in embryo of Polygordivs, 

 133 



Rosette plate, formation of, in Antedon 

 rosacea, 558 



Rostral spine of Astacus, 189 ; of Protozoaea 

 larva of Penaeus, 203 



Rotifera, development of, 418-427 



Ruffle of spermatozoon, definition of, 7 



