Development of Turris : — a, oviim of the medusiform zooid {h) 

 known as Turris ncghcta ; c, polypite, with creeping hydrorhiza, 

 developed therefrom. (All magnified.) 



Certain medusiform gonophores, and, it may- 

 be also, some true Medusids, possess the power of 

 producing, by gemmation, free-swimming forms 

 which directly resemble themselves. Such buds 

 have been observed to start from the sides of the 

 polypite in Sarsicc gemonifera and Lizzicc octo- 

 pundata, from the reproductive region of the 

 calycine canals in two species of Thaumantias, 

 from the bases of the tentacles in Steenstrupia 

 Oiuenii and Sarsia prolifera, and from the de- 

 pendent portion of the tentacles themselves in 

 Diplonema {fig. 14). Hence these medusoids 

 ought, perhaps, to be regarded as free gonoblas- 

 tidia. Here, also, it may be added, that multi- 

 plication by fission has been observed by Kolliker 

 in a species of Stomobrachium. 



