48 



THE HYDROMEDUSAE 



Fic. 5j. — Liiuiiociiida from the oral surtiUM' (afti-r Guiitlier). 



manubrium and sliallowness tif the gastric cavity, it strangely rescmliles 



many Cuninae, ami in bud- 

 ding from the mauubriuni, 

 it a]>proaches the Antho- 

 mediisae. No hydroid stage 

 lias been observed in its life- 

 history. 



Lininocodiuni, on the 

 other hand, resembles more 

 closely Lejitomedusae and 

 Trachomedusae (Figs. 52, 

 53). Its generative orgjins, of 

 which the male only have 

 been obscrvetl, are i)laced on 

 the radial canals, as in both 

 tliosse orders ; but it has a 

 hydroid stage, a thing not 

 known in any Tracho- 

 niedusan, known not to 

 occur in many Trachome- 

 dusae, and probably universal 

 among Leptomedusae ; yet 

 the firm character of the 



bell and tentacles suggest Trachomedusin athnities. 



Kio. 55n.— UiiiRrain of tin- p-niniation of tin' iiiimIu- 

 soiil of /.iiiiiiiHVKiiinii. a, cxti-nwil poUkIitiii ; h, tMiiio- 

 diTin of tli<> nuliiil caimls ; c, coflt'iitoron of tlic hydroiit ; 

 (f, cavity of railial i-anal ; r, fctiMli-riii of iiiaiiiil>riiiin ; 

 /, rudiini'iit of sul)iiiiil>nil cavity ; <;, cavity of inaiiu- 

 briiim ; A, i>ii>lo<l<'nii of niaimliriiini, »itli liliml canals 

 0); 'i ^y fctixli-rm of ciitocotlon. (Aft<'i' Kowli-r.) 



