452 Proceedings of the 



of the sac presently bursts (e), and the ova are discharged 

 into the umbrella of the medusoid (/). There they become 

 developed into ciliated larvae, and are afterwards discharged, 

 to swim away, and, after attaching themselves, become trans- 

 formed into arborescent zoophytes. 



The male capsules (fig. 4, first described by Lister) resemble 

 those of the female, but the medusoid is in a still more rudi- 

 mentary state. Its tentacles are very short and few in num- 

 ber, the lateral canals are not to be detected (Schultze and 

 myself), and the peduncle and umbrella are imperfectly differ- 

 entiated. 



The reproduction in this zoophyte has been already described 

 by Lister, Loven, and Schultze, but the anatomy of the differ- 

 ent parts has not been well distinguished. I have brought this 

 subject before the Society to point out the distinction between 

 the ovarian sac and the other parts of the medusoid, organs 

 which have been lately confounded together by Professor 

 Allman in his papers on the Reproduction of Zoophytes, and 

 as to the homology of which he appears to me to have arrived 

 at inaccurate conclusions. Wherever the medusoid form of 

 generation exists, the umbrella, with its canals, will always be 

 found not homologous with, but superadded parts to, the ovary ; 

 which last, when single, as in the present instance, represents 

 the peduncle of the medusa. Where several ovaries exist, as 

 I have shown in Campanularia Johnstoni, and shall show in 

 Laomedea geniculates, these organs are developed from the 

 lateral canals, distinct both from peduncle and umbrella, or as 

 bands between the tissues of the peduncle. 



The umbrella of a completely developed gymnopthalmatous 

 medusoid, with its canals, is the homologue of the swimming 

 organ of the Siphonophora. The Siphonophora are compound 

 medusse of the gymnopthalmatous type, in which an aggrega- 

 tion of peduncles (alimentary polyps), tentacles with their 

 bulbs (tentacular polyps), and reproductive polyps, are joined 

 together by a tubular polypary, the whole being buoyed up, as 

 in Forskalia Edwardsii (Kolliker), by a swimming organ 

 composed of numerous conjoined umbrellas, each with four 

 lateral canals. In this animal the umbrellas are altogether 

 segregated from the ovaries. In Hippopodius JYeapolitanus, 



