CNIDARIA 



69 



correlated with the disappearance of the nutritive cells. Bj 

 means of it the posterior part of the larval body (Fig. 30 C, 

 po) is characterized as the fundament of the first poljpite, 

 whereas the upper dorsal part is retained for a considerable 

 time as an embryonal remnant, which gradually diminishes 

 and is converted into the stem (like the yolk-mass of the 



Fig. 31. — Older larval stage of Eiiihulia aurantiaca (after Mkischvikoff, from 

 BA.r-FOCK'8 Comparative Embryology), so, somatocyst ; nc, second nectocalyx bud ; 

 hph, hydropbillium ; po, polypite ; t, tentacle. 



Agalmidoe). At thq same time the fundament of the necto- 

 calyx (Fig, 30 C, nc) has made considerable progress. The 

 hollow core of the bud is enveloped by a layer of entoderm 

 (hy), into which a part of the gas tro vascular cavity is pro- 

 longed as the fundament of the vessels of the bell. Another 

 entodermal process (Fig. 30 C, so) becomes the so-called 

 somatocyst {Saftbehdlter). Between the entoderm and the 



