CemmieaJ] callith amnion. 181 



The stems are very slender^ and the whole plant has a 

 fine byssoid appearance. The colour is reddish-brown. This 

 beautiful plant is intermediate betwixt C. corymhosum and 

 C. roseum. 



15. Callithamniox polyspermum^ Agarclli. 



Hab. Rocks in the sea. Annual. Spring and summer. 

 In England by Mr. Griffiths, Mr. Borrer, Dr. W. Arnott ; in 

 Ireland by Miss Ball, Mr. R. Brown, Dr. Drummond, Mr. 

 W. Thompson, Mr. Moore ; Appin, Capt. Carmichael. 



This is by far the most common CaUithamnion in the 

 west of Scotland. It is found on almost all the rocks 

 within tide-mark. It is very abundant on the piers at 

 Ardrossan, Saltcoats, Milport, and Largs. It is of a dull 

 red colour; the tufts are globose; the filaments slender; 

 the capsules very numerous, lining the inner faces of the 

 pinnse. The most interesting specimens I ever got of it 

 were on the pier at Largo in Fife; they were not much 

 above half an inch in height, but they were richly studded 

 with the largest favellae that even Mrs. Griffiths had ever 

 seen on this species. Our Ayrshire specimens adliere very 

 well to paper. 



16. Callithamnion teipinnatum, Agardh. 



Hab. On the perpendicular sides of the steep rocks at low- 

 water mark. 



