THE DEVONSHIRE CUP-CORAL." 313 



centre. The unyielding stony margin of the omachal 

 cavity preventing the morsel from being drawn down, as it 

 would be in an Actinia, the whole disk projects perpen- 

 dicularly, like a thick pillar, from amidst the tentacles, 

 displaying the dark mass through the pellucid walls. 



Now presently a great change takes place : the whole 

 of the soft tissues become distended with water, and take 

 on an exquisite translucency and delicacy ; the column 

 swells out to twice the width of the corallum, the tentacles 

 are like transparent bladders full of water, each crowned 

 by its little white globule, and the whole appearance is 

 most beautiful. I have seen under these circumstances 

 the animal extended to more than an inch and a half above 

 the level of the plates. The lip often projects like a thin 

 oval wall, or like the brickwork surrounding a well ; 

 marked with thick perpendicular ridges of opaque white, 

 distinctly defined, separated by interspaces of equal width. 

 This is well expressed in the figures (5 and 6) given by 

 Johnston, after Alder, which are very accurate : figs. 7 and 

 8 of the same plate, like too many of the zoophytic deli- 

 neations of Forbes, I can only call caricatures. 



I have elsewhere * given many details of the structure 

 and economy of this Coral, to which I can here only refer 

 the reader. Among them will be found some curious 

 examples of reproductive power ; one, in the formation of 

 a new disk, mouth, and tentacles, at the lower end of the 

 corallum, which had been broken from its base ; and 

 another, of the replacement of a large number of the 

 septa, which had been broken away. 



Of the generation and development of the species I can 



say nothing from personal observation ; the smallest I have 



seen having been about one-sixth of an inch in diameter, 



with a well-formed corallum of half a line in height. 



* Devonshire Coast, pp. 108—127. 



