INDEX 



813 



Nephridia and gonads, 487, 488 : 

 Systematic position, 512 

 Skeleton, 32* : Lobosa, 49 : Foramini- 

 fera, 55, 56 : Heliozoa, 59 : Radio- 

 laria, 63 : Flagcllata, 75 : Ciliata, 

 97, 98 : Porifera, 120 : Actinozoa, 

 200 : Sepia, 742 : Cephalopoda, 

 772, 773 See also Shell and Body- 

 wall 



Skin, 32* See Body -wall 

 Slime glands, 591 

 Slugs, 663, 715 

 Snails, 663, 715 

 Solarium, 718 

 Solecurtus strigillatus, 682 

 Solen, 692 



Solenocytes, 331*, 351, 468 

 Solenogastres, 694*, 695, 696, 697, 



698, 699, 700, 702, 781 

 Solenomya, 677 



Solpugida, 645*, 647, 648, 651, 652, 653 



Somatoblast, 440 



Somatopleure, 614* 



Spadella, 310 



Spadix, 758*, 759 



Spatangoidea, 403*, 408, 413 



Species, 1*, 114* 



Specific name, 2* 



Sperm, 21, 31* 



Spermary, 40* 



Spermatidia, 337* 



Sperrnatogeiiesis, 31* 



Spermatozoon See Sperm 



Spermiduct, 40* 



Sperm-morulse, 83* 



SpermothecEe, 303*, 452* 



Sperm-reservoirs, 471 



Sphseridia, 387*, 408, 412 



Sphseroma, 554 



Sphcerophrya, 102 



Spicules, 32*, 200, 361 



Spiders, 514, 637, 645. 648, 651, 653, 

 656 ' 



Spinnerets, 649* 



Spinning-glands, 646, 649 



Spinules, 237* 



Spinulosa, 402 



Spiral segmentation, 269* 



Spireme, 19* 



Spirifera, 360, 361 



Spirilla, 74 



Spirochcetes, 74 



Spiroloculina, 54 



Spirorbis, 477 



Spirorbis laevis, 473 



Spirula, 767, 771, 772 



Splanchnopleure, 614* 



Spongelia, 121 



Spongilla, 119 



SpongillidcB, 122, 126 



Spongin, 112*, 120, 122 



Spongin-blasts, 122* 



Sporangium (Mycetozoa), 68, 69 



Spore, 41, 50*, 69, 82, 83, 85, 87, 88, 

 89. 90 



Sporo formation, 41, 56, 61, 63, 67, 68, 



69, 82, 83, 85, 86, 87, 89, 90, 99 

 Sporocyst, 241* 

 Sporogony, 86*, 87 

 Sporosac, 151* 



Sporozoa, 46* : Example, 82 : Classi- 

 fication and general organisation, 83 

 Sporozoites, 82, 83*, 85, 86, 87- 88, 89 

 Springtails, 616, 625 

 Squame, 531* 

 Squammulina, 53, 55 

 Squids, 767 

 Squilla, 577 

 Stcecharthrum, 229 



STARFISH, External characters, 368, 

 369, 370 : Transverse section of 

 arm, 370, 371 : Vascular and nervous 

 systems, 372 : Structure of disc, 

 373 : Body-wall and coelome, 373 : 

 Digestive system, 374, 375 : Ambu- 

 lacral system, 375 : Reproductive 

 system, 378, 379 : Development, 

 380, 381, 382, 383, 384, 385, 386 : 

 Systematic position, 405 

 Starfishes, 3<i8- See Asteroidea 

 Statoblasts, 346* 

 Statocones, 689*, 765 

 Statocysts, 263*, 289, 467*, 542*. 674, 



689, 765*, 774 



Statolith, 263, 289, 467*, 689* 

 Stauromedusse, 175*, 176, 177, 224 

 Stelechopits, 477 

 Stenocyphus, 176 

 Stentor, 94, 96 

 Stephanoceros, 321, 323, 324 

 Sternal canal, 528* 

 Sternaspis, 460, 461, 464, 465, 468 

 Sternaspis spinosa, 461 

 Sternum, 528* 

 Stewart's organs, 416* 

 Stichopoda, 406 

 Stichotricha, 97 

 Stick-insects, 617, 621 

 Stigma (Euglena), 70 

 Stigmata, 593*, 607, 627, 640 

 Stinging capsule See Nematocyst 

 Stolon, 194* 



Stomach See Digestive system 

 Stomatogastric system, 437 

 Stomatopoda, 555*, '577, 578, 581 

 Stomidia, 199* 

 Stomodaeal canal, 212* 

 Stomodseum, 172*, 210 

 Stone-canal, 376*, 377, 391 

 Stony-corals, 129, 193, 199 

 Stratiodrilus tasmanicus, 331, 332 

 Strepsiptera, 625, 636 

 Streptoneura, 713*, 715, 717, 720, 722, 



724, 725, 727, 728, 729, 735 

 Streptophiurae, 403* 

 Strobila, 243*, 256 



