126 



Dr. Strethill Wright's Observations on 



Placenta adherent to summit of general Eudendrium 

 tive sac ; summit of sac furnished with arbusculum 

 cluster of large thread-cells; sac the > (male), 

 equivalent of the peduncle of Coryne E. confertum 

 gravata J (female*). 



Summit of sperm-sac furnished with a row "I Laomedea 

 of tentacles indicating the presence of a > Loveni 

 non-differentiated subumbrella J (male). 



Generative sac transformed into a free"") 



walking medusoid ; peduncle furnished | Eleutheria, 

 with branched tentacles, as in Bougain- [ medusoid of 

 villea; subumbrella not differentiated, [ Clavatella 

 its presence indicated by eye-specks (Hincks). 

 and otoliths; umbrella absent J 



Ovisac fixed, enclosed in a differentiated"! Laomedea 

 subumbrella with lateral and circular > Loveni (fe- 

 canals and tentacles J male). 



Sperm-sac surmounted with large thread- ) 

 cells, and forming the peduncle of a fixed ( Coryne gra- 

 medusoid with differentiated subum- f vata. 

 brella and umbrella J 



Imperfect free Medusa; peduncle with \ n orvne de- 

 tubular mouth, and united with a single- < c ; n £ ns 

 cavitied generative sac / <j ars i a [ 



Perfect free Medusa of low type ; pedun- 

 cle four-tentacled or lipped, and con- 

 taining eight generative sacs coalescing 

 into four, which are situated alternately 

 with the tentacles or lips 



" Bougainvillea ' 

 Britanniea, 

 the Medusa 

 of A tractylis 

 ramosa (fe- 

 male). 



Turris neglec- 

 ta, the Medu- 

 sa of Clavula 

 Gossii (fe- 

 [_ male). 

 Perfect free Medusa of low type ; pedun- ) 



cle four-lipped or tentacled, with eight ( Oceania epi- 

 distinct generative sacs, one placed on | scopalis. 

 the side of each lip j 



* In the ovisac of E. confertum (see figure in margin), 

 which I have had an opportunity of examining through 

 the kindness of Mr. Alder, the endoderm and ectoderm 

 at first adhere together at the summit of the sac, and 

 at this point a few large thread-cells occur in the ecto- 

 derm. A similar occurrence of adhesion and thread- 

 cells is found in the sperm-sac of E. arbusculum, and 

 also in the false and mouthless peduncle of the medu- 

 soid of Coryne gravata. 



" Generative 

 sac become 

 a peduncle 

 (' manubri- 

 um,' Allman). 



Subumbrella 

 l^ present, but 

 C not differ- 

 entiated. 



J 



} Subumbrella 

 differen- 

 tiated. 



( Umbrella dif- 

 f ferentiated. 



Peduncle or 

 alimentary 

 polyp and ge- 

 nerative sac 

 not differen- 

 tiated from 

 each other 

 (see post). 



Generative 

 sacs differen- 

 tiated from 

 alimentary 

 polyp, but si- 

 tuated on it. 



