ALCYONELLA. 109 



names become familiar by general recognition, we have already seen that 

 etymologies are of less avail : One correct representation is worth an hun- 

 dred etymologies. 



Plate XXIX. Fig. 1. Alcyonella stagnorum in an early stage, showing its stel- 

 late form. 



2. Specimen older, and of more compact figure, on the edge 



of a leaf of the Water Plantain. 



3. Portion with five hydra, enlarged. 



4. Portion with three hydrae, wherein their crescent form 



is exposed. 

 5, 6. Ciliated tentacula. 



7. A vigorous active hydra containing ova. 



8. Decaying hydra, distended by an internal fluid, wherein 



the ova are tossed. 



9. Ova floating obliquely. 



10. Ova floating. The sides are opening, and the halves 



sundering, a, J, c, according to the maturity of the 

 nascent hydra d. 



11. Nascent hydra farther advanced, sustained on buoyant 



particles. 



12. Ova with their hydrae far advanced, as adhering to the 



side of a vessel. 



13. Floating cluster of ova with their hydras. 



All the figures, unless the first and second of this Plate, 

 are enlarged. 



(2.) Alcyonella gelatinosa. — Plate XXX. — As neither colour nor 

 dimensions, nor even the number of external organs, are absolute guides 

 to the identity of animal productions, where all these qualities are liable to 

 be affected by age and position, the precise place of the present subject must 

 be considered provisional, until future observation may correct and em- 

 bellish its history. But I do not hesitate on its insertion here, from having 

 led to some interesting facts of another kind. 



On visiting a pond at Foulden House, in Berwickshire, during Sep- 

 tember 1831, I found various specimens of this Alcyonella. Some spread 



