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 Caryophyllice, 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 MeduscB, of a species not described by 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 

 extremely 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 mai-ginal tuber- 

 cles ; and the tentacles of the CaryophyllicBj 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- 

 phylli(B 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. 



:J: This minute structure of the tentacles is conclusive against the ani- 

 mals having been Corynactis heterocera. 



