HTDE0Z0A. 95 



by the development from its opposite sides of 

 alternate leaflets, which eventually arch over, and 

 unite with one another, forming a basket-like 



j- _ 



receptacle, or < corbula,' within which the repro- 

 ductive bodies are lodged. 



In Sertularia polyzonias and some other spe- 

 cies only one gonophore, consisting of a simple 

 J| closed sac, arises from the gonoblastidial column, 



and, by the protrusion of this sac beyond the 

 orifice of the urn, an external capsule, or Q acro- 

 cyst,' is formed, into which the ova are trans- 

 ferred at a certain period of their development 

 {fig. 19, e,f, and#). 



In Campanularia Loveni the ripe gonoblas- 

 tidium displays at its summit the medusa-like 

 gonophores already alluded to, whose form is, in 

 many respects, so peculiar that Professor Allman 

 has proposed to designate them by a distinct 

 name, 'meconidia' {fig. 10). The reproductive 

 elements of this species are developed, as in the 

 Corynidce, between the ectoderm and endoderm 

 of the manubrial wall, while in other Sertularidce, 

 with medusa-like gonophores, they arise in the 

 course of the calycine canals. 



The order Sertularidce includes two families. 



Order SEKTULAKID2E. 



Family 1. Sektulariad,e. 



Hydrothecce, and polypites, sessile. 



Family 2. CAMPANULABIADiE. 



Hydrothecw, and polypites, stalked. 



^ A more extended acquaintance with the posi- 

 tion of the nematophores may perhaps afford 

 grounds for modifying this arrangement. 



