Rhodomelece.'] polysiphonia. 293 



creeping on tlie roots of Halidrys siliqiiosa. Instead of 

 growing upright, as they usually do, they were repent, not 

 only fastened by the radical roots (if we may employ this 

 tautological expression), but throwing out roots at intervals 

 from the stem and from the branchlets, and so firmly did 

 they adhere by these that it took repeated tugs to disengage 

 them, and you heard a crackling as if you had been slitting 

 out the stitches of an old garment. In this way they lay 

 quite unaffected by any storm that did not uproot the Hali- 

 d/rys. The largest frond I observed of this creeping variety 

 was not above an inch in length ; it was much more com- 

 pressed than the erect kind, and, being a darker purple, it 

 bore a striking resemblance to Jungermannia cofiiplanata, 

 which creeps on the bark of trees. I found it also in this 

 state on the roots of Laminaria digitata, but Halidrys was 

 evidently the favourite. Creeping in this way, it is much 

 better entitled to the specific name parasiticay as it resembles 

 ivy, putting out its tendrils to cling tenaciously to trees. 



The colour is reddish-brown, becoming darker in drying. 

 There is a beautiful figure of it in ^ Phycologia Britannica,' 



PL CXLVII. 



2. Polysiphonia subulifeea, Harvey. 



Hab. In the sea. Eare. Perennial? Pound by Mrs. 



