102 THE MARINE BOTANIST. 



Polysiphonia, and are not easily disting'inshed from 

 them. Rhodomela^ with fihform inarticulate fronds, 

 contains two species : R. lycopodiodes, with fronds 

 from four to eighteen inches long, grows on the 

 stems of Laminaria digitata, and is common on the 

 northern coasts of England, Scotland and Ireland ; 

 R. subfusca is a much branched kind, with rather 

 flaccid ramuli, which adhere to paper • these drop 

 off during the winter, and the plant then appears 

 with rigid broken branches; it is a frequent species, 

 growing either on rocks or algoe : colour, in this a 

 reddish- brown, in the former a purplish-brown; 

 becoming in both species almost black when dry ; 

 the name Rhodomela, meaning red hlach, is given 

 in allusion to this change of colour. Many, or 

 almost all, of the plants of this tribe become much 

 darker in drying. The next genus, Bostrychia, 

 includes but one British species, B. scorpioides, 

 which grows either ^in the sea or in salt-water 

 ditches at the roots of flowering plants, whence it 

 was formerly known as Fttctts ampMbius, It is of 

 a pale purplish, brownish, or greenish colour, 



