148 SEAWEEDS. 



from two Greek words signifying many tubes; the 

 branches of the genus being tubular (P. elongata, Plate 

 II, jig. 3). 



An allied species of smaller size, harder texture, and 

 darker hue. lying among the rubbish, proved to be P. 

 nigrescens ; and we found the wiry branches of P. 

 fastigiata growing in abundant tufts on the stems and air 

 vessels of Fucus nodosus. This last species was of a 

 blackish brown colour. 



There are numerous species of Polysiphonia, but these 

 were all we met "with on this occasion. 



One little morsel of the beautiful Dasya coccinea 

 {Plate II, fg. 4) crowned our search. Its name 

 means hairy and red, and the main stem thread like, 

 and clothed with hair-like branches fringed with the 

 slenderest points justify the name. There are three other 

 Dasyas, one the D. venusta, very rare ; the others fre- 

 quently found. This family is the last in the order of 

 Ehodomelacaee. 



In the next order, that of the Laurenciaceae, the 

 colour is bright red, occasionally varying to pink or 

 purple. The first family is named after the French 

 naturalist Bournemaison, and contains onlv one British 

 species, a beautiful plant, with regularly arranged, taper- 

 ing, asparagus like branches. 



The true Laurencias have thickish fronds, some round, 

 some flattened ; the L. pinnatifida we found under larger 

 sea-weeds growing as minute brushwood on the sides of 

 the rock ; they were of a dark purplish crimson, pinnate 

 and toothed ; we did not find the Tufted or the Blunt 

 Laurencia. 



