460 Mrs. Thynne and Mr. Gosse on the Increase of Madrepores. 



distinguish between them, and often regretted I had not placed 

 them in separate aquaria, that I might have seen whether each 

 had multiplied in about the same degree. Wherever they came 

 from, therefore, I think they must have been the offspring of 

 the same parent. 



'' The point that raises the doubt in your mind as to their being 

 really Caryophyllia, is the absolute /ac^ that they did not during 

 two years form any corallum, or give any indication of doing 

 so, unless the chalk-like patches which occurred in the course 

 of the second year [§ 41] could be considered such. This same 

 fact also perplexed me very much; and I should have thought that 

 perhaps they would not form one at all in captivity, only that 

 they were so vigorous, and their proceedings seemed so natural 

 — the first year, fission only ; the second, fission combined with 

 gemmules : and they did not look as though they had come to 

 maturity ; for the tentacles, though most redundant in quantity, 

 were shorter and more slender than the full-grown ones. Then 

 some of the adults enlarged their corallums*, and everything 

 else appeared so thriving. The aquarium abounded with Ser- 

 pulce, that secreted their calcareous coverings ; and my arrange- 

 ments seemed to give such general satisfaction, that even the 

 Ophiura usually forgot their suicidal propensities. I had also 

 two Medusce, of a species not described l3y Mr. Forbes, which 

 lived a long time. 



" I have never seen a living specimen of any species of Cory- 

 nactis, nor read Mr. Thompson's description of it, but think it 

 exti-emely probable, as you suggest, that it may be an immature 

 form of Madrepore f. Your very beautiful drawing does not 

 exactly represent my specimens. They had no marginal tuber- 

 cles ; and the tentacles of the Caryophyllia, both young and old, 

 are also of the same shape — an opake white knobbed tip, with a 

 most delicate, transparent, granulated tube tapering towards the 

 knobbed tip J. To the naked eye the tube looks transparent, 

 with opake white spiral lines ; it is only with the microscope 

 one discovers that the apparent lines are granules. The Caryo- 

 phyllice throw off no mucus, and are much softer -looking, finer 

 in texture, and more semitransparent than any Sea-Anemones I 

 have seen. I do not know whether the Corynactis shares these 

 beauties. If the Caryophyllice really do, as I suppose, in their 

 natural state, remain two years or more without forming a 

 corallum, they would certainly be found so, if attention were 



* Thus there was no want of lime in solution in the water. — P. H. G. 



t I had suggested this as an alternative just possible, but do not con- 

 sider it as at all probable. — P. H. G. 



X This minute structure of the tentacles is conclusive against the ani- 

 mals having been Corynactis heterocern. 



