PLATE XI. 



Fig. 



1. Disc of a Velella viewed from above, and having the crest cut off. 



2. A vertical section of the pneumatocyst. It has been accidently inverted. 



3. A tentacle. 



3 fir. A part of the crest, much magnified. 



4. A small or gonoblastidial polypite. 



5. A lateral view of a young gonophore. 



6. A terminal view of the same. 



7. A more advanced gonophore. 



8. 8 a. Detached gonophores. (See PL XII, fig. 13.) 



9. A very young Velella {Rataria). 



10. Its pneumatocyst. 



1 1 . Part of its disc. 



12. A portion of its crest. 



13. A portion of the disc of a larger specimen. 



14. A still more advanced specimen. 



