INDEX 



275 



Neosporidia, 47, 57 



Nereis, 149, 157 



Nerve ring, 94, 130, 167 



Nerve tissue, 66 



Nervous system, 77, 89, 94, 105, 

 110, 125, 130, 135, 141, 146, 

 148, 167, 174, 177, 184, 189, 

 193, 204, 220, 246 

 condensation of, 246 



Nettling cells, 88, 93 



Neurite, 67 



Neuroglia, 68, 77 



Neuromotor apparatus, 35 



Neuromotor system, 52 



Neuron, 66, 77 



Neuroptera, 251 



Neuropodium, 149 



Nitzschia, 113, 125 



Noctiluca, 33, 56 



Nomenclature, international com- 

 mission on, 3 



Non-cellular organisms, 20 



Non-chordate, 1 

 phyla, 1 



Nosema, 47, 57 



Notholca, 143 



Notocotylus, 126 



Notommata, 143 



Notommatida, 143 



Notostraca, 211 



Notochord, 1 



Notopodium, 149 



Nuclear-constancy, 15, 135, 142 



Nuclearia, 57 



Nucula, 201 



Nuda, 101, 103 



Nudibranchs, 194, 196 



Nyctotherus, 57 



Nymph, 238 



Nymphon, 231, 234 



O 



Obelia, 102 

 Occiput, 239 

 Ocellus, 79, 226, 239 

 Octocoralla, 98, 100 

 Octopoda, 200, 201 

 Ocular plates, 175 



Odonata, 251 



Olfactory organs, 79, 146, 184, 240 



Oligochaeta. 147, 150, 152, 157 



Oligotricha, 57 



Olynthus, 83 



Ommatidia, 79 



Onchosphere, 120 



Oniscus, 222, 223 



Onycophora, 205, 231, 234 



Oocapt, 120 



Oogenesis, 11 



Ookinete, 45 



Ootype, 114 



Opalina, 49, 57 



Opercularia, 58 



Operculum, 152, 160, 192, 196 



Ophioderma, 182 



Ophionereis, 182 



Ophiopholus, 175 



Ophiothrix, 182 



Opisthorchis, 126 



Ophiura, 175, 182 



Ophiuroidea, 166, 174, 182 



Ophrj'odendron, 58 



Ophisthobranchia, 195, 196, 201 



Oral shields, 175 



Orb weavers, 228 



Orbicella, 103 



Orchestia, 222, 223 



Organ systems, 68 



Organellae, 22 



Organogenesis, 117 



Organs, 68 



Oriental sore, 37 



Orthasterias, 182 



Orthonectidae, 60 



Orthoneurous, 194 



Orthoptera, 251 



Oscarella, 83, 87 



Osculum, 82 



Osphradia, 184, 189 



Ostium, 211, 220 



Ostracoda, 209, 214, 223 



Ostrea, 201 



Otocyst, (see statocyst), 80 



Otolith, 63, 80 



Overgrown development, 247 



Ovicells, 161 



Oviducts, 76 



