30 ON TFIE AFFINITIES OF TFIE FAMILY OF THE MEDUS^i 



Fig. 7. A single buccal tentacle much magnified. 



Fig. 8. A portion of the marginal canal with a tentacle and t« o marginal corpuscles. 



P"ig. 9. Portion of the marginal canal {a) with young tentacle (i), and a marginal vesicle 



containing two corpuscles, each enclosed within a delicate cell-wall. 

 P'ig. 10. A marginal vesicle highly magnified ; the two corpuscles do not appear to ha\'e 



attained their full development, as they refract less, and the cell appears more 



opake. 



Oceania ? 



Fig. II. Lateral view of the animal. 



Fig. 1 1 u. Vertical section. 



Pig. 12. Part of the under surface of the disc. 



a. Marginal membrane. 



/'. Canals and generative organs. 



I. Common cavit)'. 



Part of the membrane surrounding the mcuth. 



The edge of this much magnified. 



Part of the margin of the disc much enlarged. 



a. Marginal membrane. 



b. Canal and generative organs. 

 I. Tentacles. 



d. Marginal corpuscles. 



e. Circular canal. 



Fig. 16. Portion of the ovarium so folded as to have its inner membrane (a) outward.?. 

 Fig.' 17. Sectional view of the ovarium. 



a. Inner membiane. 



/'. Outer membrane. 



(. Ovum. 



(f. Germinal vesicle. 



£. Germinal spot. 



Pl. XXXVIII. [Plate 3.] 



P'lait'/lOj ho}-a ? 



Fig. iS. View of a segment of the under surface. 



a. Marginal vesicles. 



b. Tentacles in this individual very much shorter than usual. 



c. Ovary or testis. 



d. Buccal membrane. 

 Fig. iS a. \'ertical section. 

 Fig. 19. Tentacle. 



I'ig. 20. Portion of the buccal membrane. 



Fig. 20 a. Round processes containing thread-cells scattered over its outer surface. 



Fig. 21. Portion of the testis. 



a. Generative tentacles. 

 Fig. 22. Sectional view of part of the testis. 



u. Otiter membrane. 



h. Sperm-sacs. 



c Inner membrane. 

 Fig. 23. Stages of development of the spermatozoa (45). 

 I'ig. 24. Ovarium. 



a. Outer membrane. 



b. Ova. 



£. Inner membrane. 



