GOLD MADREPORE. 403 



If any additional evidence were wanting to show 

 that this species approaches much nearer the Actiniae 

 than C. Smithii does, it would be found in the stony 

 skeleton. This is very different in appearance from 

 that of the kindred species, and is manifestly rudi- 

 mentary. When the soft parts have been carefully 

 removed by several days' maceration in fresh water, 

 and the gelatinous matter all cleared away from the 

 stony plates by a slender stream of water allowed to run 

 upon it from a height, a vertical view shows the following 

 arrangement : — First, at the very margin there is a 

 narrow circle of white calcareous plates, small and 

 very irregularly anastomosing, so as to resemble in 

 miniature the honey- combed limestone rock that we 

 find around Torquay and elsewhere. In the centre of 

 the cavity, there is another loose spongy mass of 

 similar irregular plates. Eighteen perpendicular radi- 

 ating plates extend between the marginal circle and 

 the central mass, arranged in six threes, so as to make 

 a six-rayed star. The order of each trine series is as 

 follows : the middle one is the thickest and shortest, 

 reaching scarcely more than half-way from the cir- 

 cumference to the centre. On each side of this there 

 is a longer thinner plate, neither parallel nor converg- 

 ing towards the centre, but diverging at a small angle, 

 so that each of these lateral plates meets the lateral 

 plate of the next trine series, at a point consider- 

 ably short of the centre, whence a plate sometimes 

 goes to the central mass. The arrangement will be 

 better understood by a reference to Plate XXVI, fig. 

 6, whit3h represents a quadrant of the circle, much 

 magnified. 



