Index. 



Sinistral shells, 276, 283. 

 Sinupalliata, 270. 

 Siphodentalium, 273, 274. 

 Sipho, 208. 

 Siphonactinia, 114. 

 Siphonaria, 312. 

 Siphonizantia, 381. 

 Siphonal tentacles, 259. 

 ganglion, 215. 

 Siphonodentalium, 273. 

 Siphonophora, 96, 382. 

 Siphonosphaera, 64. 

 Siphonostomata, 308, 347, 361. 

 Siphuncle, 314, 315. 

 Sipunculidae, 192. 



Sipunculus, 189, 190, 191, 192, 193. 

 Sirex (Uroceridae), 421. 

 Sisyra, 406. 

 Sitaris, 414. 

 Slabberia, 91. 

 Slugs, foot gland of, 296. 

 Smaragdinella, 305. 

 SmjTitriurus, 387. 

 Socialia, 404. 

 Solanderia, 123. 

 Solarium, 309. 

 Solaster, 136-7. 

 Solemya, 256. 

 Solen, 260, 266. 

 Solenidrv, 271. 

 Solenobia, 36. 

 Solenogorgia, 123. 

 Solenonema, 185. 

 Solifugae, 365. 

 Solpuga, 365, 377. 

 Somatic cavity, 85. 

 Somatocyst, 197. 

 Somites, 327. 

 Soritidae, 54. 

 Soroideae, 51, 55. 

 Spadix, 86, 317. 

 Spatangidae, 139, 145, 147. 

 Spatangus, 139, 148. 

 Spatha, 262. 

 Species, 37. 



Species, number of living, 46. 

 Spence Bate, 46, 354. 

 Spermaceti, 8. 

 Spercheus, 415. 

 Spermategae, 179. 

 Sphaerechinus, 138. 

 Sphaeridia, 145. 

 Sphaerites, 246. 

 Sphaeria, 167. 



Sphaerodorum, 222. 

 Sphasronidae, 362. 

 Sphaeronectes, 98. 

 Sphaeronectidae, 98. 

 Sphaerotherium, 381. 

 Sphaerozoum, 64. 

 Sphaerularideae, 179. 

 Sphex, 420. 

 Sphenoderia, 53. 

 Sphenopus, 114. 

 Sphenotrochus, 412. 

 Sphingidae, 400. 

 Sphinx, 412. 

 Sphyrocephalus, 160. 

 Spicules, 75. 

 Spiders, 364. 

 Spines, 140. 

 Spine warts, 138. 

 Spiniger, 

 Spio, 222. 



Spiochactopterus, 219. 

 Spirachtha, 386. 

 Spin 



Spirilla, 9. 

 Spirifer, 250. 

 SpirifcridiL', 2^4. 



lus, 381. 

 Sj)irillina, 56. 

 Si'injchwui, 70, 79. 

 Sjtirolina, 55. 



tera, 184. 

 :bis, 223. 



tomum, 67, "I. 

 Spiruhi, 315. 

 Spirulina, 50. 

 Spirulirostra, 315. 

 Spirura, 184. 

 Spiruridae, 184. 

 Spondylidoe, 270. 

 Spondylus, 270. 

 Spondylostomum, 

 Spongelia, 77. 

 Sponges, 72. 

 Spongia, 76. 

 Spongilla, 78. 

 Spongioderma, 123. 

 Spongobranchia, 275, 277. 

 Spongiolin, 8, 75. 

 Spongocyclinae, 63. 

 Spongodes, 119. 

 Spongodictyum, 63. 

 Spongodiscidinae, 63. 

 Spongosphaerinae, 63. 

 Spongotrochus, 



