INDEX 



687 



tion of, in Annelida, 321 ; in Cerebratuhts 

 lacteus, 1'20 ; in Dentalium, 328'; in Dreis- 

 sensia, 337 ; in adult Bntoproota, 386 ; in 

 Bchiuroidea, 163 ; in Paludina, 310 ; in 

 Patella, 293, 297 ; in Polygordius, 134 ; 

 in Sipunculus, 380 



Protozoa, 20, 30 



Protozoaea larva of Euphausia, 203 ; of 

 Pencceus, 203 



Pseudozoaea stage in development of Stoin ato- 

 poda, 218 



Pulmonata, 291, 320 



Pupa of Cirripedia, 202 ; of Donacia, 260 ; 

 of Galerticellaulmi, 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, in 



Pyloric gland, formation of, in Qiona in- 

 testinalis, 625 



Pyloric sac, formation of, in Asterias, 471 



Pyrosoma,6S7 , 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 o( Planocera, 

 106 ; in segmenting egg of Polygordius, 

 133-139 



Radial canals of medusa of Tubularia, 68 



Radial cells in embryo ol Polygordius, 135 



Radial nerve-cords, formation of, in Ophio- 

 thrix fragilis, 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 Amphiura 

 squamata, 499 ; in Asterina gibbosa, 479 



Radial sliields, formation of, in Amphiura 

 squamata, 499 



Radial water -vascular canals, formation of, 

 in Antedon rosacea, 549, 556 ; in Asterias, 

 471 ; in Cucumaria planoi, 542; in Ophio- 

 thrix fragilis, 492 ; in Synapta digitata, 

 533, 539 



Radiating muscles, formation of, in Poly- 

 gordius appe7idiculatus, 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 



RathJcea, 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 

 Pedieellina, 400 



Recurrent coil of intestine, formation of, in 

 Echinus esculentus, 520 



Reducing division, definition of, 6 

 Regeneration of eye in Shrimps, 286 

 Renilla renifornis, 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 



^4si!a(;«s,189; iu Dytiscus,'2,1 6; in Limulus, 



237 

 Retraction of polar-lobe in egg o{ Dentalium, 



326 

 Retractor muscles of foot, formation of, in 



Dreissensia, 342 ; of funnel, in Loligo, 



361 ; in larva of Polygordius appendica- 



latus, 148 

 Reversion, jDrocess of, in development of 



Agelerui., 227 ; in development oi Donacia, 



259 ; in development oi Periplaneta, 260 

 Rhabdites of Tungia, 115 

 Rhabditis larva of Ascaris megalocephala, 



447 ; of Nematoda, 454 

 Rhabdocoela, 102, 115 

 Rhabdocoelida, 102 

 Rhabdome, formation of, in eye of AgeUna, 



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 Beriie, formation of, 92 

 Right anterior coelom of larva of Asterias, 



467 ; of larva of Echinus esculentus, 509 ; 

 of lari'a 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 Aurelia, 



71 

 Ripe ovum, definition of, 9 

 Rosette-cells in embryo of Patella, 294 ; 



formation of, in embryo of Polygordius, 



133 

 Rosette plate, formation of, in Antedon 



rosacea, 558 

 Rostral spine of /4stoc«s, 189; of Protozoaea 



larva of Penaeus, 203 

 Rotifera, development of, 418-427 

 Ruffle of spermatozoon, definition of, 7 



