xu 



LIST OF THE WOOD-CUTS. 



Majjnified view of marginal tentacles ....... 



Splicrical embryo ........... 



The same, somewhat more advanced ....... 



Tlie same before it becomes attacheil ....... 



Group of embrjos attacheil, in diH'erent stages of development . 

 Different stages of growth beyond those of Fig. 213. .... 



Profile of MiiLtCEniUM georgicum, natural size .... 



Digestive cavity and point of junction of the chymiferous tubes 

 Staukophor.\ lacixiata, having eight tentacles .... 



Quarter of the disk of a young Staurophora, with sixteen large tentacles 



Young Medusa somewhat more advanced than Fig. 216' . 



Different stages of actinostome intermediate between that of Figs. 215* and 219 



Young Stauro])hora, having the aspect of the adult 



Profile view of Ptychogexa lactea, somewhat reduced .... 

 Magnified view of the genital organs, seen from the abactinal pole 



Same as Fig. 221, seen in profile 



Actinostome . 



Magnified base of tentacles and club-shaped appendages 



Cluster of Dvxamena plmila. (L. Agassiz.) 



Magnifieil portion of stem of Fig. 225. (L. Agassiz.) 



Young Ne.mop^is Baciiei, with four tentacles 



Somewhat more advanced Xemopsis. . 



Magnified view of the sensitive bulb ........ 



Nemopsis in which the genital organs extend a considerable distance along the 



chymiferous tubes . . 



Magnified view of the genital organs, the actinostome, and the oral tentacles 

 Magnified profile view of adult Bougaixvillia Sf perciliaris . 

 Ilydromedusarium of BougainviUia ........ 



Young elongated Medusa 



Somewhat more advanced than Fig. 234 



Appearance a short time before separating from the stem .... 



Same as Fig. 236, expanded 



Young BougainviUia, immediately after its liberation from the Ilydromedusarium 



Magnified view of sensitive bulb 



Tentacular bulb, with young tentacles 



Adult Mahgelis carolixexsis, seen in profile, magnified 



Digestive cavity, genital pouches, oral tentacles, and actinostome . 



Sensitive bulb at base of one of the chymiferous tubes 



Young Margelis, having only two marginal tentacles at the base of each chvuiit' 



erous tube ........... 



Young Margelis, seen from the abactinal pole, in condition of Fig. 244 . 

 Proboscis of a Margelis, having already six tentacles at each sensitive bulb 

 Hydrarium, greatly reduced in size ....... 



Alagnified heads and Medusae buds of JIargelis carolinensis .... 



Female Medusae buds of Eudexdrium dispar, in different stages of development 

 Part of a male colony of EuDEXDUirM texue, magnified .... 



Adult male of LizziA grata, seen in profile, magnified 

 Quarter-disk of a young Lizzia ....... 



Magnified view of sensitive bulb 



Proboscis of male Lizzia, magnified ....... 



One of tln^ four lobes of the actinostome, seen from above . 



Actinal view of proboscis of young Lizzia 



Actinal view of proboscis of an older specimen .... 



Abactinal view of Fig. 257, somewhat less magnified 



Adult Dvsmorpiiosa fulgur.\xs, magnified .... 



Magnified proboscis, showing young Medusiv of the second and third generations 

 TmtRis V'ESKWRiA, natural size, seen in profile .... 



The same, with the bell contracted ....... 



A i)ortion of the disk, seen from the abactinal pole 



133 

 134 

 134 

 l.'!4 

 134 

 134 

 135 

 135 

 136 

 136 

 136 

 136 

 137 

 138 

 138 

 138 

 138 

 138 

 141 

 141 

 149 

 1.50 

 150 



150 

 151 

 153 

 154 

 154 

 154 

 154 

 154 

 154 

 155 

 155 

 156 

 156 

 156 



157 

 157 

 158 

 158 

 1.58 

 159 

 160 

 Ifil 



ii;i 



161 

 162 

 162 

 162 

 162 

 162 

 163 

 163 

 165 

 165 

 165 



