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MR. T. H. HUXLEY ON THE AFFINITIES OF THE MEDUSA. 
Fig. 19. Tentacle. 
Fig. 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. 
a. Outer membrane. 
b. Sperm-sacs. 
c. Inner membrane. 
Fig. 23. Stages of development of the spermatozoa (45.). 
Fig. 24. Ovarium. 
a. Outer membrane. 
h. Ova. 
c. Inner membrane. 
Fig. 25. Marginal vesicle from the under surface. 
a. Dilatation of the canal. 
Fig. 25 a. Marginal vesicle and pedicle very much enlarged. 
Rhizostoma mosaica. 
Fig. 26. View of the under surface of the disc, the brachiferous plate being cut away 
a. Marginal vesicles. 
h. Cut extremity of the suspending pillar of the brachiferous plate. 
c. Central crura. 
d. Lateral crura. 
e. Generative folds. 
f. Connecting membrane. 
Fig. 26 a. Vertical section of the Rhizostoma. 
Fig. 27 . Side view of the brachiferous plate detached. 
PLATE XXXIX. 
Rhizostoma mosaica. 
Fig. 28. Extremity of one of the ultimate ramifications of the arms. 
a. Thick substance of the outer membrane. 
h. The central common canal. 
c. The lateral canals leading to the apertures. 
d. The fringes. 
Fig. 29. Lateral view of one of the apertures much magnified. 
a. Thick outer membrane. 
b. Inner membrane. 
c. Lateral canal. 
d. Tentacles. 
