INDEX 



689 



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

 bratulina septentrionalis, 413 



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

 in larva of Ixntiiliiim, 329 ; in larva of 

 Dreissensia, 335 ; in embryo of Loligo, 

 357 ; in larva of Patella, 299 



Siphonoglyphe, definition of, 83 



Siphonophora, 53, 161 ; development of, 

 64-66 



Sipunculoidea, 163, 372, 406 



Sipuncidus, 385 ; development of, 380 



Slime glands, formation of, in Peripatus 

 capensis, 175 



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



Solaster endeca, 457, 529 ; development of, 

 482 



Solenocytes of archiiiephridium of Poly- 

 gordius, 140 ; of larval kidneys of Gastro- 

 poda, 323 ; of nephridia of Amphioxus 

 lanceolatus, 600 ; of nephridiuni in Poly- 

 gordius, 138 



Soleiiogastres, 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 of Donacia, 251 ; in 

 embryo of Peripatus capensis, 171 



SpadeUa, 428 



Spadella draco, 433 



Spadix of medusa of Tubularia, 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 



Sphaer echinus, 525, 526 



Sphaerechinus granularis, 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 Agelena, 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; ateggofPolyffordiug, 129-139 



Spiral twisting of Palv.dina, distinguished 

 from torsion, 316-317 



Splauchuocoele, formation of, in Amphioxus 

 lanceolatus, 595 



Spongilla, development of. 47 



Spongilla lacustris, 50 



Sqname 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 Pedicellina, 403 ; in larva of 

 Terebi-atulina, 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 Scolopendra, 

 282 



Stigmata, formation of, in dona intestinalis, 

 628 ; in Donacia, 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 dona intestinalis, 

 625 ; in Dentalium, 328 ; in Loligo, 364 ; 

 in Cyphonautes larva of Membranipora, 

 389 ; in larva of Ophiothrix fragil is, 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 lanceolatus, 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 JSalanoglossus clavigerus, 

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

 Crepidula, 323 ; in larva of Ciicumaria 

 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 

 Membranipora, 389 ; in J\ 7 ephelis, 160 ; 

 in larva of Ophiothrix fragilis, 487 ; in 

 Paludina, 310 ; in Patella, 298 ; in Pedi- 

 cellina, 400; i\\ 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 Gallerucelli ulmi, 269 



Stomotaca apicata, development of, 61 



Stone-canal., formation of, in A ntedon rosacea, 

 550; in Asterias, 469; inAsterinagibbosa, 

 474 ; in Echinus esculentus, 510 : of Ophio- 

 thrix frag His, 491 ; in Ophiurabrei-ispina, 

 501 ; in Synapta digitata, 533 



Strepsinema, definition of, 4 



