INDEX OF SUBJECTS. 



659 



da, 298; Gastrotricha, 196; Hirudi- 

 nea, 329; Insecta, 492; Nematoda, 

 174, 178; Pelecypoda, 333; Tra- 

 cheata, 469 



myocoel, 610 



myophanes, 35 



Nauplius, 417 



nectocalyx, 91 



Needham's pouch, 355 



neinatocyst, 77 



iiephiidia (see Excretory System) 



nephroblasts, 226, 337 



nervous system — Acautbocephala, 

 181; Amphiceura, 387, 290; Arach- 

 nida, 437 ; Bracbiopodii, 271 ; Ce- 

 pbalochorda. 614; Cephalopoda, 

 350 ; Cestoda, 155 ; Chgetognatha, 

 187 ; ChiBtopoda, 208, 231 ; Crusta- 

 cea, 378; Cteuophora, 124; Binophi- 

 lus, 199 ; Echinodera, 185 ; Echlno- 

 derma, 539 ; Enteropneusta, 605 ; 

 Gasteropoda, 300; Gastrotridia, 197; 

 Gephyrea, 239; Hirudinea, 333; Hy- 

 dromedusae, 80; Mollusca, 281 ; My- 

 zostom 686,244; Nematoda, 175, 179; 

 Nemertina, 163 ; Pelecypoda, 334; 

 PeDtastoraidas, 461 ; Phoronid8B,347; 

 Platy hel minthes , 128 ; Polyzoa, 257 ; 

 Porifera, 73 ; Pterobranchia, 599, 

 600 ; Pycnogonida, 465 ; Rotifera, 

 193 ; Scapbopoda, 333 ; Tracheata, 

 471 ; Trematoda, 144; Turbellaria, 

 131, 133, 137 ; Urochorda, 623; Xi- 

 phosura, 430 



neuroblasts, 226, 237 



nidameutal gland, 313, 355 



notochord — Cephalooborda, 613 ; 

 Enteropneusta, 603; Pterobranchia, 

 599, 600; Urochorda, 625 



nuclein, 3 



nucleolus, 6 



nucleus, 5 



nymph, 456 



Odontoblasts, 280 



olfactory organ — Cephalopoda, 353 ; 

 Chffitognatha, 188 ; Mollusk, 383 ; 



Bcyphomedusae, 100 ; Tracheata, 

 472; Xiphosura, 432 



ommatidium — Chaelopoda, 209 ; 

 Crustacea, 381; Insecta, 472; Pele- 

 cypoda, 337; Xiphosura, 431 



ooecia, 363 



ootyp, 146 



operculum— Gasteropoda, 296; Poly- 

 zoa, 363; Scorpionida, 443; Xipho- 

 sura, 439 



organ, 41 



organs of Bojanus, 337 ; of Cuvier, 

 588; of Stewart, 576 



orthoueurism, 310 



osculum, 69 



ospbradlum, 283 



otocysts — ChsBtopoda, 309 ; Crusta- 

 cea, 383 ; Ctenophora, 122 ; Holo- 

 thuroidea, 589 ; Hydromedusse, 82, 

 84, 85, 86; Mollusca, 383 ; Scypho- 

 medusK, 99; Turbellaria, 131, 133, 

 134; Urochorda, 635 



ovary, 44 



ovicell, 363 



ovum, 44 ; Fertilization of, 49 ; Ma- 

 turation of, 46; Segmentation of 

 51 



Psedogenesis, 60, 499 



pali, 107 



palpi, 205 



parapodia, 204, 313 



paratrocb, 313 



parenchyma, 128 



Parenchymella, 55 



parthenogenesis, 60, 498 



paxillse, 553 



pentines, 443 



pedicellariae, 574 



pedipalps, 435 



Peniactcea, 591 



pereiopod, 410 



pericardial glands, 398, 337, 345 



pericardium, 378, 437 



perisarc, 79 



peritoneal cells, 205 



phaosphere, 439 



phosphorescence, — Crustacea, 382; 



