INDEX 



689 



in Patella, 300 ; in Sepia, 357 ; in Tere- 

 hratuUna septentnonalis, 413 



Shell-gland, formation of, in Cyclops, 199 ; 

 in larva of Dentalium, 329 ; in larva of 

 Dreissensia, 335 ; in emtryo of Loligo, 

 357 ; in larva of Patella, 299 



Siphonoglyphe, definition of, 83 



Siphonophora, 53, 161 ; development of, 

 64-66 



Sipunculoidea, 163, 372, 406 



Sipuncvlus, 385 ; development of, 380 



Slime glands, formation of, in Peripatus 

 capensis, l75 



Solaster, 459, 481, 484, 501, 565, 656 



Solaster eiideca, 457, 529 ; development of, 

 482 



Solenocytes of archinephridinm of Poly- 

 gordius, 140 ; of larval kidneys of Gastro- 

 poda, 323 ; of nephridia of Amphioxtis 

 lanceolatus, 600 ; of nephridinm in Poly- 

 gordius, 138 



Solenogastres, 291 ; ancestor of, 368 ; de- 

 velopment of, 324-325 



Somites, definition of, in Polygordius, 145 ; 

 formation of, in embryo of Amphioxus 

 lanceolatus, 594 ; in embryo of Astacus, 

 187 ; in embryo ot Donacia, 251 ; in 

 embryo of Peripatus capensis, 171 



Spadella, 428 



Spadella draco, 433 



Spadix of medusa of Tuhularia, 58 



Spatangoidea, 511, 565 



Spermatid, definition of, 6 



Spermatocyte of first order, 6 ; definition of, 

 3 ; of second order, definition of, 6 



Spermatogenesis, definition of, 2 



Spermatogonium, definition of, 3 



Spermatozoon, definition of, 2 ; formation 

 of, 6, 7 



Sphaereckinus, 525, 526 



Sphaerechinus granulans, 504 



Sphaeridia, formation of, in Echinus escu- 

 lentus, 520 



Spiders, 282 



Spinal cord, formation of, in Amphioxus 

 lanceolatus, 593 ; in larva of Cynthia 

 partita, 619 



Spines, formation of, in Echinus esculentus, 

 515 



Spinnerets, formation of, in Agelejia, 231 



Spinning glands, formation of, in Agelena, 

 231 



Spioniformia, 128 



Spiral caecum, formation of, in Loligo, 365 



Spiral cleavage of egg of Cerebratulus lacteus, 

 119 ; of egg of 'Dreissensia, 333:335 ; of 

 egg of Patella, 293-295 ; of egg of Phas- 

 coloma, 373-374 ; of egg of Planocera, 

 104-108; of egg of Polygordius, 129-139 



Spiral twisting of Paludina, distinguished 

 from torsion, 316-317 



Splanchuocoele, formation of, in Amphioxus 

 lanceolatus, 595 



Spongilla, development of, 47 



Spongilla lacustris, 50 



Squame of antenna in Zoaea larva of 

 Caridea, 210 



Stalk, formation of, in larva of Antedon 

 rosacea, 548 ; in larva of Asterias, 469 ; 

 in larva of Pedicdlina, 403 ; in larva of 

 Terebratulina, 412 



Star-fish, sperm of, used to cross fertilize 

 eggs of Sea-urchin, 17 



Stercoral pocket, formation of, in Agelena, 

 230 



Sternaspis, 153 



Sternum, development of, of Scolopendro, 

 282 



Stigmata, formation of, in Ciona intestinalis, 

 628 ; in Bonacia, 258, 259 



Stolon, formation of, in Diplosomidae, 642 ; 

 in Doliolum, 639 ; in Pyrosoma, 639 ; in 

 Salpa, 639 ; in Urochorda, 638 



Stolonial budding in Urochorda, 638-641 



Stomach, formation of, in Agelena, 235 ; in 

 adult Asterias, 469, 471 ; in larva of 

 Asterias, 462 ; in larva of Balanoglossus 

 clavigerus, 573 ; in Ciona intestinalis, 

 62,5 ; in Dentalium, 328 ; in Loligo, 364 ; 

 in Cyphonautes larva of Membranipora, 

 389 ; in larva of Ophiothrix fragilis, 487 ; 

 in larva of Pedicellina, 400 ; in larva of 

 Polygordius, 142 ; in larva of Synapta 

 digitata, 532 



Stomatopoda, 177, 219 ; development of, 

 216-218 



Stomocoele of Amphioxus loMceolatus, 606 



Stomodaeum, definition of, 76 ; formation 

 of, in Agelena, 226 ; in Amphioxus lanceo- 

 latus, 604 ; in embryo of Antedon rosacea, 

 547 ; in Ascaris megalocephala, 444 ; in 

 Astacus, 183, 184 ; in larva of Asterias, 

 462 ; in larva of Balanoglossus clavigerus, 

 573 ; in Beroe, 94 ; in Bombyx, 279 ; in 

 Orepidula, 323 ; in larva of Cuciimaria 

 planci, 542 ; in Dentalium, 328 ; in 

 Donacia, 252, 253 ; in Dreissensia, 336 ; 

 in adult Echinus esculentus, 515 ; in 

 larva of Echinus esculentus, 508 ; in 

 Fiona, 323 ; in Cyphonautes larva of 

 Memh-anipora, 389; in Nephdis, 160; 

 in larva of Ophiothrix fragilis, 487 ; in 

 Paludina, 310; in Patella, 298; in Pe*'- 

 cellina, 400; in Peripatus capensis, 175; 

 in Phascolosoma, 376 ; in Physa, 324 ; in 

 Planocera, 109; in Polygordius, 137-138, 

 323 ; in Sagitta bipunctata, 431 ; in larva 

 of Synapta digitata, 532 ; in Terebratulina 

 septentrionalis, 410 ; in Unio, 352 ; in 

 Urticina crassicornis, 79 ; metamorphosis 

 of, in larva of GalleruceUi ulmi, 269 



Stomotaca apicata, development of, 61 



Stone-canal, formation of, in Antedon rosacea, 

 550; va. Asterias, 469; xaAsterinagibbosa, 

 474 ; in Echinus esculentus, 510 ; of Ophio- 

 thrix fragilis, 491 ; in Ophiura brevispina, 

 501 ; in Synapta digitoAa, 533 



Strepsiuema, definition of, 4 



