PLATE X. 



Fig. 1. Profile view of a large Porpita measuring 1 ^" in diameter, with the tentacles swung under 

 the flisk and the disk thrown up. 



Fig. 2. Disk seen from above to show the arrangement of the tentacles of a young Porpita, measuring 

 about ^" in diameter. 



Fig. .3. Magnified portion of a part of the disk of Fig. 2, and of the corresponding marginal tentacles ; pp, 

 proliferous polypites. 



Fig. 4. Portion of the lower side showing the mouth of the central polypite m, and the rows of repro- 

 ductive polypites pp, with the tubules tt, extending over the base of the central polypite. 



Fig. -i. ^Magnified view of a portion of the disk showing the central polypite q), fuOy expanded, with the 

 rows of reproductive polypites pp, between the base of the central polypite and the marginal 

 tentacular polypites tp. 



Fig. 6. Magnified \-iew of a small reproductive feeding polypite 2^P, '^^'itli a cluster of medusae in differ- 

 ent stages of development, and with the meamlering tubules extending over its base. 



Fig. 7. Extremity of one of the largest marginal tentacular polypites, showing the arrangement of the 

 tentacular knobs. 



Fig. 8. Magnified view of one of the tentacular knobs. 



Fig. 9. Folds of the actinal opening of the central polypite. 



Fig. 10. Profile view, showing the arrangement of the tentacular marginal polypites. 



Fig. 1 1. Different stages of growth of the smaller marginal tentacular polypites. 



