INDEX OF SUBJECTS. 



659 



da, 298; Gastrotricha, 196; Hirudi- 

 nea, 229; lusecta, 492; Nematoda, 

 174, 178; Pelecypoda, 332; Tra- 

 cheata, 469 



myoccel, 610 



myophanes, 35 



Nauplius, 417 



uectocalyx, 91 



Needham's pouch, 355 



nematocyst, 77 



uephridia (see Excretory System) 



nephroblasts, 226, 237 



nervous system Acautbocephala, 

 181; Amphiueura, 287, 290; Arach- 

 nida, 437 ; Brachiopoda, 271 ; Ce- 

 pbalochorda. 614 ; Cepbalopoda, 

 350 ; Cestoda, 155 ; Chaetognatha, 

 187 ; Chaetopoda, 208, 221 ; Crusta- 

 cea, 378; Cteuophora, 124; Dinophi- 

 lus, 199 ; Echinodera, 185 ; Echiuo- 

 derma, 539 ; Enteropneusta, 605 ; 

 Gasteropoda, 300; Gastrotricha, 197; 

 Gepbyrea, 239; Hirudiuea, 232; Hy- 

 dromedusse, 80; Mollusca, 281 ; My- 

 zostomese,244; Nematoda, 175, 179; 

 Nemertina, 163 ; Pelecypoda, 334; 

 Pentastomidac, 461 ; Pborouidae,247; 

 P]atybelminthes,128; Polyzoa,257; 

 Porifera, 73 ; Pterobrauchia, 599, 

 600 ; Pycnogonida, 46o ; Kotifera, 

 192 ; Scapbopoda, 323 ; Tracbeata, 

 471 ; Trematoda, 144; Turbellaria, 

 131, 132, 137; Urocborda, 623; Xi 

 pbosura, 430 



rieuroblasts, 226, 237 



nidamental gland, 312. 355 



notochord -- Cephalochorda, 612 ; 

 Enteropueusta, 603; Pterobranchia, 

 599, 600; Urochorda, 625 



nucleiu, 3 



nucleolus, 6 



nucleus, 5 



nympb, 456 



Odontoblasts, 280 



olfactory organ Cepbalopoda, 353 ; 

 Chaatognatha, 188 ; Mollusk, 282 ; 



Scypbomedusae, 100 ; Tracbeata, 

 472; Xipbosura, 432 



ommatidium Chaelopoda, 209 ; 

 Crustacea, 381; lusecta, 472; Pele- 

 cypoda, 337; Xipbosura, 431 



ocecia, 263 



ootyp, 146 



operculuru Gasteropoda, 296; Poly- 

 zoa, 262; Scorpiouida, 442; Xipbo- 

 sura, 429 



organ, 41 



organs of Bojanus, 337 ; of Cuvier, 

 588; of Stewart, 576 



orthoueurisin, 310 



osculum, 69 



osphradium, 283 



otocysts Cbaelopoda, 209 ; Crusta- 

 cea, 383 ; Cteuopbora, 122 ; Holo- 

 tburoidea, 589 ; Hydromedusse, 82, 

 84, 85, 86; Mollusca, 283 ; Scypbo- 

 rnedusse, 99; Turbellaria, 131, 132, 

 134; Urocborda, 625 



ovary, 44 



ovicell, 263 



ovum, 44 ; Fertilization of, 49 ; Ma- 

 turation of, 46; Segmentation of 

 51 



Pasdogenesis, 60, 499 



pali, 107 



palpi, 205 



parapodia, 204, 313 



paratrocb, 213 



pareucbyma, 128 



Parencbymelia, 55 



parthenogenesis, 60, 498 



paxillae, 553 



pectines, 442 



pedicellarise, 574 



pedi palps, 435 



Pentactifa, 591 



pereiopod, 410 



pericardial glands, 298, 337, 345 



pericardium, 278, 437 



perisarc, 79 



peritoneal cells, 205 



pbaospbere, 439 



phosphorescence, Crustacea, 382; 



