Nerve, 101 auditory, 117 optic, 118 Nerve-cells, 103, 187 fibres, 101, 188 Nervous system, 105 development of, 213, 224 functions of, 354 Noble crayfish, see _Astacus nobilis_ Nomenclature, binomial, 13, 15 Norway lobster, see _Nephrops_ Novozelanian province, 314 Nucleated cell, 199 Nucleolus, 187 Nucleus, 177, 200 changes of, in cell-division, 200 O. Œsophagus, 51 Olfactory organ, 114 Organ, 22 Origin of crayfish, evidence as to, 320, 331 Ovary, 31, 129 structure of, 131 Oviduct, 129 Oviposition, 351 Ovisac, 132 Ovum, 129 structure of, 133 P. Palæarctic province, 314 _Palæmon_, 268, 328 _Palinuridæ_, 263 _Palinurus_, 261, 264 Palp, 171 _Paranephrops_, 250, 306, 313 Paraphragm, 158 Parasites of crayfish, 356 _Parastacidæ_, 252, 256, 306, 313 _Parastacus_, 250, 306 _Pemphix_, 341 _Penæus_, 267, 280 Pericardium, 69 Perivisceral cavity, 50 Phyllobranchia, 271 Physiology, 46 Pleurobranchia, 79 Pleuron, 96, 143 Podobranchia, 75, 165 _Podophthalmia_, 279 Pore-canals, 195 Post-orbital ridge, 233 spine, 232 _Potamobiidæ_, 252, 256 Prawn, see _Palæmon_ Prehension of food, 49 Procephalic lobes, 160 development of, 213 Propodite, 165 Protopodite, 143 _Prototroctes_, 315 {370} _Protozoa_, 285 _Pseudastacus_, 343 Pylorus, 52 R. Race, 292 RATHKE, quoted, 356 RÉAUMUR, quoted, 33 Reflex action, 108 REICHENBACH, quoted, 356 Renal organ, see Green-gland Reproduction of lost limbs, 38 sexual, 39, 128, 135, 350 Reproductive organs, 128 development of, 225 Respiration, anal, 353 Respiratory organs, see Branchiæ _Retropinna_, 315 ROBIN, quoted, 352 Rock lobster, see _Palinurus_ ROESEL VON ROSENHOF, quoted, 41, 43 RONDOLETIUS, referred to, 4 Rostrum, 157 development of, 217 S. Salivary glands, 352 _Salmonidæ_, parallel between their distribution, and that of _Astacidæ_, 315 Sarcolemma, 90, 182 SARS, G. O., referred to, 327 SARTORIUS VON WALTERHAUSEN, quoted, 322 Scaphognathite, 80, 170 Schizopod stage of development, 280 SCHLÜTER, 317 SCHMIDT, O., quoted, 354 SCHRANK, 290 Science, physical, 3 Science and common sense, 1 Segmentation, 174 Self-causation, 112 Sensory organs, 113 Septal line, 183 zone, 183 Setæ, 197 Shrimp, see _Crangon_ SIEBOLD, VON, referred to, 331 Sight, organ of, 118 Sinus, sternal, 69 Smell, organ of, 114 Somite, 143, 161, 355 abdominal, 142 cephalic, 154 thoracic, 150 SOUBEIRAN, M., quoted, 349 Southern Crayfishes, 249 Species, 243, 290 morphological, 291 physiological, 296 Spermatozoa, 129, 135, 354 Spontaneous action, 112 Squame of antenna, 172 Steinkrebs, see _Astacus torrentium_ Sternum, 96, 143 Stomach, 29, 51 Stone-crayfish, see _Astacus torrentium_ Striated spindle, 121 Swimmeret, 20 T. Taste, organ of, 115 Teleology, 47, 137 Tendon, 92, 175 {371}