PLUMATELLA. 137 



Plate XXXII. Fig. 11. Group of the ova floating. 



12. Nascent hydrse from the ova ; the shells seen to the right 



still adhering. 



13. Nascent hydra from the ovum, among other ova still 



entire. 



14. Portion of fig. 10, as on May 17 of the following year, 



or seven months later than the date of that drawing, 

 shewing the hydrce now nascent, with ova still entire 

 interspersed. 



15. Nascent hydra of the young brood. 



16. Branches of a specimen of the Plumatella from Black- 



hall pond, containing ova. 



1 7. Group of the ova, from the same, floating. 



18. Hydra of a specimen of Plumatella from Lochmill. 



All the figures of this Plate, except the first and the 

 eighth, are enlarged. 



Plate XXXIII. Fig. J. Plumatella repens on a stone from Blackhall pond. 



2. Another specimen. 



3. Single hydra subsisting after the decay of others. 



4. Hydra and an ovum affected by its rise and fall. 



5. Branch with the whole hydrse from one side. 



6. Skeleton of a young specimen, which bore twelve white 



hydrse in winter. 



7. Branch of the specimen, Plate XXXI., with hydne 



and ova. 

 8, 9. Ova of the same floating. 



All the figures, except fig. 6, are enlarged. 



VOL. II. 



