ULVACE^. 249 



minutely midribbed form {P. linearis of Greville) will 

 be found. This is succeeded, often in the same locality, 

 by the broader, waved fronds of the form which has 

 been hitherto considered the type of this species. These 

 again, in deeper water, and as the season advances, pass 

 by scarcely perceptible degrees through several interme- 

 diate states into the extremely expanded, divided plant 

 that is known as P. laciniata. In almost every locality, 

 generally near the influx of some freshwater stream, 

 the filmy, fragile fronds of this species are to be found, 

 floating helplessly in the eddies caused by the advancing 

 or receding waves, or spreading themselves in purple, 

 shining patches over rocks, stones, or mud when the 

 tide is out. As distinct as they are common, there can 

 be no doubt as to their identity, for there is no other 

 British sea- weed that they at all resemble. They are, 

 however, difiBcult to preserve, for they do not, as a rule, 

 adhere closely to paper, and require heavy and long- 

 continued pressure and careful drying. Even after the 

 most skilful and patient treatment they will hardly bear 

 a momentary exposure to the air without beginning to 

 curl up and crack. Laver, sloke, or sloukawn, as it is 

 variously called in England, Scotland, and Ireland, is 

 made by boiling the fronds of this species for several 

 hours. It is afterwards fried, and eaten with vinegar 

 and pepper; and although by no means a tempting 

 dish to the eye, it is, I believe, both palatable and 

 wholesome. 



Genus CVIII. BANGIA. 



Fronds hair-like, composed of numerous cellules, which 

 radiate from a central cavity, and are enclosed in a con. 



