PLATE VIII. 



Fig. 1 . A portion of the disk of a Porpita, showing the white plate with its spongy ramifications i, extend- 

 ing into the liase of the feeding and reproductive polypites {cp,fp), ivith the so-called liver I, 

 placed between the lower floor of the chambers of the float c, and the spongy upper part of 

 the white plate ; with the tubules t, extending from the lower side of the float through the 

 mass of the liver, many of them passing through the white plate and extending along the base 

 of the feeding and reproductive polypites. 



Fig. 1'. General view showing the relative position of the white plate i, the liver I, the chambers of 

 the float c, and of the tubules of the upper and lower side of the plate. 



Fig. 2. A cluster of feeding and reproductive polypites: t, tubules extending along the base ; m, medusae 

 buds in difl'erent stages of development. 

 A single reproductive polypite with two very young medusae buds h b. 

 Actinal opening of one of the feeding polypites. 

 A single reproductive polypite with dustei-s of medu-SK m, in different stages of development and 



the tubule t, extending more than half the length of the polypite towards its extremity. 

 Different view of a single reproductive polypite, with two clusters of medusae. 

 Young medusa just freed from the reproductive polypite: d, canal leading to the cavity of the 

 polypite through the base of attachment; y, clusters of yellow cells; c, large lasso-cells. 



FiG. 7. Young medusa, somewhat older, more elongate, lettering as in the previous figure. The lasso- 

 cells extend along the sides of the bell. 



Fig. 8. Young medusa, stage intermediate between Figs. 6 and 7. 



Fig. 9. Same seen from above. 



Fig. 10. Fig. 6 seen from above. 



Fig. 11. Fig. 7 seen from above. 



Fig. 12. Abactinal part of the bell of Fig. 7 : ch, chymiferous tubes ; d, rudimentary digestive cavity. 



Fig. 13. Portion of the edge of the bell of a medusa in the stage of Fig. 7, lettering as before. 



Fig. 14. One of the large lasso-cells of the surface of the bell with the coil partially thrown out. 



Fig. 15. Young medusa still attached to the reproductive polypite. 



Fig. 16. A portion of the free edge of the mantle : d, edge of the disk; g, one of the marginal glands. 



Fig. 16". View from the lower side of the disk, to show a portion of the ramifications of the liver. 



Fig. 17. Fatty globules filling the marginal glands. 



