1XDEX. 



719 



Solitaire, 547 . 



Somateria mollissima, 543 



Somite, 266 



Sorex platyrhiuus, 587 



Sounds produced by insects, 349 



Sounds, tisbes', 442 



Spalax, 586 



:Sparrow, 555 



Spatangus, 206 



Specialization, 6 



Species, origin of, 672 



variation of, 10, 672, 673 

 Spermaceti, 593 



Spermatozoa, formation of, 644 

 Sphserodorum, 231 

 Spbargis coriacea, 510 

 Sphenodon, 511 

 Spueotyto cunicularia, 549 

 Sphex ichueumonea, 363 

 Sphinx, 359 

 Spiders, 342 

 Spirialis Gouldii, 239 

 Spirula Peronii, 261 

 Sphyrna zygtena, 421 

 Spirorbis, 175 

 Sponges, 42 



silicious, 47 



useful, 49 

 Spongia adriatica, 49 



equina, 49 



gossypina, 49 



tubulifera, 49 

 Spongilla, 47 

 Spoonbill fish, 428 

 Sporocyst of Nematodes, 109 

 Spring-tails, 344 

 Squalus Americanus, 420 

 Squamella oblonga, 176 

 Squid, anatomy of, 273 

 Squilla, 292 

 Squirrels, flying, 583 

 Sur-fish, 178, 191, 193 



anatomy of, 178 

 Star-worm, 159 



Statoblast, 145 

 Stegocephala, 482, 488 

 Steller's manatee, 596 

 Stentor polymorphic, 36 

 Sternum of insects, 309 

 Stick insect, 677 

 Stickleback, 456 

 Stilt, 546 

 Sting rays, 424 

 Stomapoda, 292, 305 

 Stone lilies, 183 

 Strobila of Hydrozoa, 66 

 Strobila of Planarians. 102 



tape-worms, 114 



Strobihitioninworms, 102, 10:5, 172 

 Struggle for existence, 673 

 Struthio camelus, 539 

 Sturgeon, embryology of, 427 

 Sturgeon, 427 

 Stygicola dentata, 459 

 Stylaster, 58 

 Styliola vitrea, 238 

 Stylochus elliptica, 101 

 Stylocordyla, 48 

 Stylops, 353, 354 

 Sucker, 453, 454 

 Suctoria, 40 

 Sun-fish, fresh water, 455 



banded, 455 



spotted, 456 



salt-water, 462 

 Swimming, in fishes, 444 

 Sycandra, 44 

 Sycon ciliatum, 45 

 Syllis, 215 



Symmetry, bilateral, in cteno- 

 phores, 92, 93 



echinoderms, 202 

 Symphyla, 344 . 

 Synapta, 216, 217 

 Syncarida, 272 

 Syuguathus peckianus, 461 

 Synthetic types, 483, 679 

 Syrinx, 526, 552 



