LIST OF THE WOOD-CUTS. xiii 



Fig. 264. Magnified profile view of genital organs and actinostome 165 



" 265. Magnified view of a part of a chymiferous tube . . . ." . 166 



" 266. Base of one of the chymiferous tubes, and part of the circular tube . . .166 



" 267. One of the tentacles, in a profile view 166 



" 268. One of the tentacles, seen from the abactinal pole . . . . . .166 



" 269. Young TURRITOPSIS NUTRICULA, with four marginal tentacles . . . 167 



" 270. Somewhat more advanced, having sixteen tentacles ....*.. 167 



" 271. STOMOTOCA ATRA, somewhat magnified, seen in profile ..... 169 



" 272. Magnified view of genital organs . . . . . . . . . .169 



" 273. Stomotoca atra . ............ 169 



" 274. CLAVA LEPTOSTYLA. (L. Agassiz.) 170 



" 274 a . Young WILLIA ORNATA, having only the second set of tentacles developed . 171 



" 275. Young Willia, nearly in the stage of Fig. 276, seen from the abactinal pole . .171 



" 276. Profile view of a young Willia . ......... 172 



" 277. Part of the circular tube . . . . . . . . . . .172 



" 278. View of ovary of Fig. 276 172 



" 279. Same as Fig. 278, seen from the abactinal pole . . . . . . .172 



" 280. PROBOSCIDACTYLA FLAVICIRRATA 173 



" 281. Actinostome and digestive cavity . . . . . . . . . .173 



" 282. Portion of disk to show mode of branching of chymiferous tubes, and tubes con- 

 taining lasso-cells, as in Willia . . . . . . . . 1 74 



" 283. Adult CORYNE MIRABILIS, seen in profile. (L. Agassiz.) . . . . 175 



" 284. Coiyne, with proboscis contracted. (L. Agassiz.) . . . . . .175 



" 285. Coryne, with expanded proboscis. (L. Agassiz.) . . . . . . 175 



" 286. Cluster of Hydraria of Coryne mirabilis. (L. Agassiz.) 176 



" 287. Young Hydrarium of Coryne. (L. Agassiz.) ....... 176 



" 288. Magnified view of head, with Meduste buds attached. (L. Agassiz.) . . .176 



" 289. CORYNE ROSARIA, natural size 177 



" 290. Hydromedusarium of SYXDICTYON RETICULATUM, greatly magnified . . .178 



" 291. Syndictyon reticulatum, immediately after it has become freed from the Hydro- 



medusarium, in profile . . . . . . . . . .178 



" 292. One of the tentacles of Fig. 291, magnified 178 



" 293. Sensitive bulb of Fig. 291 178 



" 294. Digestive cavity of Fig. 291 .178 



" 295. Fig. 291, from actinal pole 178 



" 296. Fig. 291, from abactinal pole . 179 



" 297. Part of net-work of lasso-cells of surface of spherosome . . . . .179 



" 298. Adult Medusa in a natural attitude 180 



" 299. Same Medusa (Fig. 298) with the tentacles contracted 180 



" 300. Actinostome of adult Medusa 180 



" 301. Young DIPURENA CONICA . . . . . . . . . . .181 



" 302. Digestive cavity of a young Dipurena conica . . . . . . . 181 



" 303. Tentacle of Dipurena conica .......... 182 



" 304. Digestive cavity of a Medusa in which the constriction has already separated the 



upper and lower halves . . . . . . . . . .182 



" 305. Adult Dipurena conica, in which the two digestive cavities are widely separated 182 



" 306. Profile view of half a young GEMMARIA GEMMOSA 184 



" 307. Profile view of GEMMARIA CLADOPHORA, magnified 184 



" 308. Quarter-disk of same, seen from the abactinal pole . . . . . .185 



" 309. Actinostome of Gemmaria, enlarged ........ 185 



" 310. Cluster of lasso-cells of the marginal tentacles . . . . . . .185 



" 311, Fertile Hydra of PENNARIA TIARELLA 187 



" 312. Medusa distended by eggs 187 



" 313. Profile view of Medusa of Pennaria tiarella . . . . . . . 187 



" 314. Different attitude of the Medusa, seen from the actinal pole 188 



" 315. Fig. 313, seen from the abactinal pole 188 



" 316. EUPHYSA VIRGULATA, seen in profile 190 



" 317. Magnified proboscis of Fig. 316 190 



" 318. Actinal view of Euphysa virgulata ......... 190 



