HALF AN HOUR WITH CORALLINES. 



95 



Fig. 46. 



This species seems to be confined to the northern 



coasts of Britain, where it is parasitically attached 



to others. There are three other species of Diphasia, 



of which one, cdata, is very rare. D. pinnata and D. 



pinaster are peculiar, the former being confined to 



the coasts of Devon and 



Cornwall, where it occurs 



in deep water. Its height 



is about six inches, and, 



when dry, its colour is 



dark. The cells or caly- 



cles are rather small, 



springing but little from 



the stem, and having a 



wide, even mouth (Fig. 46). 



The capsules are produced 



freely, the male being 



only one-third the size of 



the female, and bluntly 



toothed at .their apex. 



The female capsules are 



egg-shaped, and divided 



by four longitudinal lines into four distinct lobes. 



D. pinaster includes what have been considered 



to be two distinct species. Its colour is a light 



brown, and it grows to a height of from two to 



six inches. The cells are cylindrical, the upper 



half being turned abruptly outwards. The male 



capsules are ovate, and almost four square in the 



upper portion, having a spine at each angle. On 



Diphasia pinnata, magnified. 



