170 SEAWEEDS. 



E. clathrata, forming an entangled silky tuft of narrowest 

 threads, and E. ranmlosa, as intricately tufted, but 

 rough to the touch, were both adorning the rock pools 

 at Arran. Of the other species we have no examples. » 



The Ulvas have flat outspread fronds. The common 

 Ulva (Lattissima, Cut I., Jig. 8), is bright, green, and 

 much waved ; it grew plentifully on rocks at Granton, 

 making them dangerously slippery. The U. lactea is 

 smaller and paler. The narrow, U. linza we did not find. 

 The Porphyras were there also ; the P. laciniata with its 

 divided fronds, and the P. vulgaris with its large simple 

 ones, both which are purple and glossy, and are called by 

 children "sea silk." These plants make a wholesome dish 

 when cooked, and are sold for that purpose by the name 

 of Laver in various districts. According to Lightfoot, 

 Ulva latissima is employed in the Scottish Highlands to 

 bind about the temples in fevers, and is thought to 

 induce sleep ; and in the Western Isles it is stewed with 

 pepper, vinegar, and onions as a dinner dish. 



These Ulvas are most ornamental plants in tide pools 

 and shallows : their bright green hue setting off the 

 crimson of the Callithamnion, and the lilac the Cor- 

 alline to the greatest advantage. 



" How varied the hues of marine vegetation, 

 Thrown here the rough flints and sea-pehbles among ; 

 The feathered Plocamium of deepest carnation, 

 The dark purple Sloke and the olive Sea-thong." 



The Bangias are minute weeds ; they vary, as the 

 Porphyras do, from the established green of the class, to 

 bright purple ; they are little more than encrustations. 



