472 



SUBJECTS INDEX 



Ophryotroeha, 277, 278, 280, 313, 



316. 

 OrthonectidBe, 206. 



relationships of, 215. 

 Orthoptera, sexual cells of, 12. 

 Oscarella, 20, 22, 28, 3i. 

 Otomesostoma, 177. 

 Oxysoma, 236. 



Paractinia3, 93. 



Parenchymula, 22, 41. 



Peachia, 94. 



Pelagia, 105, 118, 122. 



Pelagidie, 120. 



Pennaiia, 47. 



Pennatula, 83, 87. 



Pentacta?a, 458, 459. 



Peromedusffi, 123. 



Person, 1. 



Phalangidae, sexual cells of, 12. 



Phascolosoma, 357, 364. 



Phialidium, 49. 



Phorouis, relationships of, to 



Sipunculidte, 365. 

 Phyllochsetopteras, 274. 

 Phyllophorus, larva of, 419. 

 Physalia, .59, 62, 74, 75. 

 PhysonectsB, 59, 75. 

 Physophora, 64. 

 PhysophoridiB, 59, 60, 67. 

 Pietocystis dythiiidium, 195. 



variabilLs. 195. 

 Pileolaria, 279,- 300. 

 Pilidium, 217. 



auriciilatum, 220. 



brachiatum, 220. 



gyrans, 220. 



recur vatum, 220. 

 Placina, 14. 

 PlakinidfB, 22, 28. 

 Planaria angulata, 169. 



polychroa, 169. 

 Planula, 14. 

 Platyhelminthes, 159. 

 Plerocerci (Taeniadas), 195. 

 Plerocercoids (TiBuiadoe), 195. 

 Plcurobrachia. 138. 

 PleurochtKta, 291. 

 Pluteus, 422, 4i4. 

 Piieumatophorida), 59, 62. 

 Polar globules, 3. 



ingressioa, see Ingression, 

 l^olar. 

 Pole, animal, 3. 



vegetative, 3. 

 Polia, 228. 



Polychsera, 262. 

 Polycladida, 160, 173. 174. 

 Polygordius, 263, 267, 268, 237, 



290, 292, 295. 

 Polylophns, 34. 

 Polyuoe, 262. 

 Polyopsis, 93. 

 Polypbyidae, 71, 72. 

 Polvpodium, 49. 

 Polystomidffi, 188, 190. 

 Polvstomum, 188. 

 Polytrochfe, 271, 273. 

 Pomatoceros, 3, 263. 

 Porifera, 13, 28, 32. 

 Porpita, 59, 65. 

 PorpitidsB, 65. 

 Pray a, 71. 



Primary germ-layers, 5. 

 Primitive mesoderm cells, 10. 



mouth, see Blastopore. 

 Prorhynchus, 173. 

 Pi'ostonia, see Blastula. 

 Prostomial discs (Pilidium), 221, 

 Pi'ostomum lineai'e, 173, 175. 



Steenstrupii, 173, 174. 

 Protaxonia, 9. 

 Protodrilus, 287. 

 Pi'otohydra, 49. 

 Protozoa, 11, 

 Protiila, 302. 

 PseudoceridsB, 160. 

 Pseudocoele, 11. 

 Pseudogastrula, 17. 

 Psolinus, 419. 

 Psygmobrauchus, 263, 275, 279, 



284, 291, 297, 299, 300. 

 Pteraster, brooding iu, 436. 



Raspailia, 24, 

 Ratariae, 65. 

 Rathkea (Fig. 13), 40. 

 Redia (Distomidie), 183. 

 Reniera, 24, 27. 

 Renilla, 76, 83, 88. 

 Rhabditis, 238. 



aoeti, 235. 



nigrovenosa, 234, 242. 



stercoralis, 242. 

 Rliabdoccela, 159. 

 RhabdoccelidfB, 159, 173, 174. 

 Rhabdonema, 242. 

 Rhizocriuus, 453. 

 Rhizophysa, 59. 75. 

 Rhizostoma, 120. 

 Rhizostomne, 124. 

 Rhizoxonia, 82. 

 Rhopalouema, 57. 



