THE DEVONSHIRE CUP-CORAL. 311 



are wanting in some of the systems. They are broad, granular on 

 both surfaces, with the upper edge very salient and rounded in outline. 

 Those of the third and fourth cycles subequal between themselves, and 

 much smaller than the first and second, which also are mutually subequal. 



Columella. From twelve to twenty thin plates much twisted, with 

 sinuous edges ; the summits much lower than the palules. 



Palulcs. Well-developed, more flexuous than the septa, of which they 

 correspond to the third cycle. 



Colour. In general pure white, but in some specimens tinged with 

 a lovely permanent rose-tint. 



ANIMAL. 

 Form. 



Column. Cylindrical, very extensile, smooth, membranous, invected 

 towards the summit, each invection becoming a tentacle, without any 

 distinct margin. 



Disk. Flat, but readily assuming a conical form. No trace of gonidial 

 radii, tubercles, or groove. 



Tentacles. About fifty in number, arranged in three subequal rows: 

 stem conical, membranous, translucent, studded with transverse oblong 

 warts ; head globose, opaque, covered with palpocils. (Plate xii. fig. 4.) 



Mouth. A lengthened ellipse or a slit. Lip coarsely furrowed, like the 

 lips of a cowry-shell. Stomach flat when empty, as in Anemones. 



All the tissues can be enormously distended with water. 



Colour. 



Column. A very faint bay or fawn colour, with longitudinal lines of 

 chestnut. 



Disk. Transparent white, with a broad Vandyked circle of rich 

 chestnut surrounding the mouth. 



Tentacles. Stem-wall colourless, with the warts deep chestnut ; head 

 opaque, pearl-white, sometimes slightly tinged with rose. 



Mouth. Pure white. 



Size. 



Corallum. Fine specimens attain a diameter of three-fourths of an inch, 

 and a height nearly as great. 



Animal. The column when distended frequently stands an inch above 

 the corallum, and exceeds it in breadth by a sixth of aD inch on every 

 side ; the tentacles augment the height still further by nearly half an inch. 



Locality. 



On various part3 of our coast in deep water, attached to stones and 

 shells : Devon and Cornwall, on rocks between tide-marks. 



