Plate 10. 



Charybdea rastonii, from preserved specimens. 

 Fig. 1. Side view of half grown specimen, 13 mm. in diameter. 

 Fig. 2. Aboral view of same, showing exumbral sculpture. 

 Fig. 3. Oral view of same, with tentacles cut off ; (c.v) velar canal ; (fr) frenulum ; (t) 



stump of tentacle. 

 Fig. 4. Side view of rhopalium in its natural position in the exumbral nitch ; (oc), otocyst. 



X20. 

 Fig. o. Oral view of rhopalium, X 40. (o 1 , o 1 ) single ocelli; (o 2 , o 2 ) paired ocelli. 

 Fig. 6. Somewhat ideal dissection of apex of bell, to show depth of gastric cavity and 



absence of mesenteries. 

 Fig. 7. One of the gastric phacellae, X 30 ; to show type of branching. 



Atolla wyvillei. 

 Fig. 8. Oral view of central portion of the disc. On the right-hand side the lower gastric 



wall and the gonads are dissected away to show the gastric filaments (g.f) ; gastric 



ostia (g.os) ; ring sinus (r.s); and septal node (s.n); (go) gonad. Natural size. 

 Fig. 9. Aboral view of central portion of disc of a specimen 8 mm. in diameter, in which 



the radial furrows are narrow, as in A verrillii ; the number of furrows is one 



less than of tentacles, (ped) pedalium ; (t) tentacle. 



