MUSEUM OF COMPARATIVE ZOOLOGY. 287 



e. Sac (subumbral). 



/. Margin of the bell. 



gf. Gastral filaments. 



h. Patches of pigment. 



i. Substance of the hell. 



k. Pouches. 



Is. Row of pigment-spots on the walls of the stomach. 



o. Ovary. 



p. Chymiferous reservoirs. 



p\ Oral tentacles. 



ot. Otocyst. 



so. Sexual openings through which the ova are discharged. 



PLATE IV. 



Fig. 1. "Sense area" (Beroe ovala). 



2. Halitiara formosa. 



3. Ephyra (?) of Lincrgcs Mercurius. (Quadrant of disk from below.) 



4. Ephyra (L. Mercurius) younger than fig. 3. 



5. Ovaries and subumbral pouches (L. Mercurius). 



6. Subumbral pouch (L. Mercurius adult). 



7. 8, 9, 10, 11, 12. Eggs and stages of their segmentation (L. Mercurius). 



13. Planula (L. Mercurius). 



14. Ephyra (?), (L. Mercurius). 



15. Ephyra more developed than fig. 3. (Octant.) 



16. Marginal sense body of ephyra (i. Mercurius). 



17. The same (side view). 



18. 19. Marginal sense body (L. Mercurius adult). 



20. Gastral filaments (L. Mercurius). 



21. Tentacle and bell margin (L. Mercurius). 



22. Single marginal tentacle (L. Mercurius). 



PLATE V. 



Fig. 



