562 
Psalistops, 389 
Psechridae, 399 
Psechrus, 399 
Pseudalibrotus, 137 
Pseudidiops, 388 
Pseudocuma, 121 ; distribution, 215 
Pseudocumidae, 727 
Pseudoniscus, 279 
Pseudopallene, 511, 537 ; 
540; P. spinipes, 537 n. 
P. circularis, 
Pseudoscorpiones, 258, 430 f.; habits, 
430; external structure, 431, 432; 
internal structure, 433 ; development, 
434, 435; classification, 486 ; British 
species, 438 
Pseudo-stigmatic organs, 467 
Pseudozoagza, larva of Stomatopod, 143 
Pterocuma, 121 
Pterolichus, 466 
Pteronyssus, 466 
Pterygometopus, 249 
Pterygotus, 283, 291, 292; P. osiliensis, 
290 
Ptychoparia, 247 
Pucetia viridis, 419 
Pupa, of Cirripedia, 81, 82 
Purcellia, 448 
Pychnogonides, 501 n. 
Pyecnogonida, 507 f. ; body, 505; chelo- 
phores, 505; palpi, 507; ovigerous 
legs, 507; glands, 511; alimentary 
system, 513; circulatory system, 516 ; 
nervous system, 516; eyes, 517; in- 
tegument, 518; reproductive organs, 
519; eggs, 520; development, 520; 
habits, 524 ; systematic position, 525 ; 
classification, 528 f.; British species, 
540 f. 
Pyenogonidae, 539 
Pycnogonum, 503, 539; P. australe, 540; 
P. crassirostre, 540; P. littorale, 501, 
540, 541; P. magellanicum, 540; P. 
magnirostre, 540 ; P. microps, 540; P. 
nodulosum, 540; P. orientale, 540; P. 
philippinense, 540; P. pusillum, 540 ; 
P. stearnsi, 540 
Pygidium, 235 
Pylocheles, 180; P. miersii, 173 
Pylochelidae, 780 ; habitat, 204 
Pylopagurus, 180 ; relation to Lithodidae, 
aCe, alg} 
Pyrgoma, 92 
Rachias, 388 
Railliet, on classification of Pentastomids, 
495 
Ranina dentata, 188 
Raninidae, 7SS8 
Rastellus, 320, 387 
Ratania, 68 ; mouth, 63 
Réaumur, 360 4 
Recurved eyes, 316 
INDEX 
Red spider, 455, 472 
Red-water, 456 
Regeneration, of Crustacean limbs, 155, 
156 
Regillus, 414 , 
Reichenbach, on embryology of Astacus, 
12 
Reighardia, 495, 497 ; hosts of, 497 
Remipes, 171; R. scutellatus, 171 
Remopleurides, 232, 247; R. radians, 229, 
248 
Reproduction (incl. Breeding), of Clado- 
cera, 43 f.; of Amnaspides, 116; of 
Lobster, 156; of Limulus, 274; of 
Spiders, 365 ; of Ticks, 461 ; of Pyeno- 
gons, 520 
Reproductive (generative) organs, of Crus- 
tacea, 15; of Phyllopods; 31; of 
Cladocera, 43; of Arachnids, 257 ; of 
Limulus, 271; of Scorpions, 305 ; of 
Spiders, 333; of Solifugae, 428; of 
Phalangidea, 446 ; of Acarina, 461 ; of 
Tardigrada, 482; of Pentastomida, 
492 ; of Pyenogons, 519 
Respiration, of Crustacea, 16; of Anas- 
pides, 115; of Albunea, 170; of 
Corystes, 170, 189; of Birgus, 174 ; 
of Oxystomata, 186, 187; of Cato- 
metopa, 194, 195; of Arachnids, 256. 
(See also Respiratory organs. ) 
Respiratory organs, of Arachnids, 256 ; 
of Limulus, 269, 270; of Eurypterids, 
288; of Scorpions, 305; of Spiders, 
336 ; of Tardigrada, 482; of Penta- 
stomida, 491. (See also Respiration. ) 
Rhagodes, 425, 429 
Rhagodinae, 429 
Rhax, 429 
Rhipicentor, 469 
Rhipicephalus, 469; R. sanguineus, 470 
Rhizocephala, 94 f. ; compared with Mon- 
strilla, 66 ; with Anelasma, 89 ; castra- 
tion caused by, 100; males, 106; 
association with Entoniscidae, 136 
Rhomphaea, 402 
Rhopalorhynchus, 532; R. clavipes, 533 ; 
R. kre. -ri, 533.5; R. tenuissimus, 533 
Rhynchothoracidae, 535 
Rhynchothorax, 505, 533; R. 
5386; R. mediterraneus, 
536 
Ricinulei, 439 
Robber-crab, 173 
Roncus, 436, 438 
Rucker, 423 
Rudolphi, on Pentastoma, 488 n. 
australis, 
508, 535, 
Sabacon, 451 
Sabelliphilus, 71 
Sacculina, 95 ; life-history, 96 f. ; males, 
99; castration caused by, 100 f. ; S. 
carcini, 96; S. neglecta, Nauplius, 97 ; 
