720 



INDEX 



Sexual differences and sexual be- 

 haviour (cont.) 

 ofEchinodermata,629; oflnsecta*, 

 446, 469, 470, 472, 479 ; of Myria- 

 poda, 422, 424 ; of Nematoda, 250 ; 

 of Onychophora, 321 ; of Panto- 

 poda, 539; of Polychaeta, 278; of 

 Protozoa, 32 ; of Rotifera, 240. 

 See also Generative organs 



Sexual reproduction, 6 ; of Metazoa, 

 see Generative organs ; of Protozoa, 

 30. See also Life history 



Sexuparae, 480 



Shape of body, see Body 



Shell of Crustacea, see Carapace 



Shell of Echinoidea, see Corona 



Shell glands, of Crustacea, see Maxil- 

 lary glands; of Platyhelminthes, 

 210 



Shell ligament, 573 



Shell types, Arenaceous, 75 ; Imper- 

 forate, 75 ; Perforate, 75 



Shells, of Brachiopoda, 613 ; of Crus- 

 tacea, see Carapace; of Foramini- 

 fera*, 13, 72, 74, 75, 75, 7^; of 

 Mollusca*, 545, 547, 548; 549-605 

 (passim); of Protozoa, 12 



Shield-shaped tentacles, 649 



Sialis, 485 ; lutaria, 485 



Sicula, 170; 171 



Sida, 363 



Silicoflagellata, 50 



Silicoflagellidae, see Silicoflagellata 



Silver fish, see Lepisma saccharina 



Simocephalus , 364 ; sima, 365 



Simuliidae, 509 



Simulium, 446 



Sinus system of Hirudinea, 298 



Sinuses, Haemal, of Arachnida*, 

 522, 531; of Arthropoda, 314; of 

 Crustacea, 348; of Helix, 556; of 

 Lamellibranchiata, 580 ; oiLumbri- 

 culus, 293, 294; of Pomatoceros, 

 etc., 263 



Siphon, of Echinoidea, 646 ; of 

 Gasteropoda, 556; of suctorial 

 Crustacea, see Proboscis 



Siphonoglyphes, 182 



Siphonophora, 166; 154, 167, 168 



Siphonozooids, 185 



Siphons of Lamellibranchiata, 574 



Siphuncle, 602 ; 600 



Sipunculoidea, 304; 261, 301 



Sipunculus, 303, 304 



Sirex gigas, 500 



Sitaris, 458 



Size of Protozoa, 8 



Skeletal plates, of Echinoidea, 641 ; 

 of Ophiuroidea, 638 



Skeletogenous layer, 117 



Skeleton, External, see Corals, Cuti- 

 cle, Perisarc, Shell ; Internal, see 

 Internal skeleton 



Skin, 136 



Skull of Cephalopoda, 596 



Slimonia, 524; 525 



Small intestine of Insecta, 434 



Social life, of Hymenoptera, 498, 

 502 ; of Isoptera, 469 



Soldiers of Isoptera, 469; 471 



Solenia, 183 



Solenocyte, 275; 134 



Somatoblast, 282 



Somite, First, of Arthropoda, 306-7, 

 308, 309, 318, 319, 332, 420, 425, 



515 

 Somites (body segments). Series of, 



in Arthropoda, 306-7, 308; in 



Crustacea, 328-9; in Polychaeta*, 



266, 268, 270, 272. See also 



Tagmata 

 Somites, mesoblastic, see Mesoderm 



segments 

 Spatangoida, 647 

 Spatangus, 648 



Sperm pouch of Chaetognatha, 619 

 Sperm sacs, see Seminal vesicles 

 Spermatheca (Receptaculum sem- 



inis), of Helix, 561 ; of Insecta, 447 ; 



of Nematoda, 250; of Platyhel- 

 minthes, 210 

 Spermatic atrium, 291 

 Spermatophores, of Crustacea, 352; 



of Helix, 561 ; of Peripatus, 321 ; of 



Sepia, 598 

 Spermatozoa, 6; of Crustacea, 352; 



of Hirudinea, 300; of Nematoda, 



250 

 Spermiducal glands of Oligochaeta, 



287 

 Sphaeractinomyxon, 102 

 Sphaerella, see Haematococcus 

 Sphaerophrya, 116; 115; sol, 108 

 Sphecoidea, 503 

 Spherularia, 257 ; 256 

 Sphex, 503 

 Sphingidae, 491 

 Sphinx, 439 



