CRYPTOGAMIAALG^E. 247 



GREV. Alg. Brit. 165. Ulva purpurascens, WITH. iv. 142. U. 

 fastigiata, WALKER'S Essays, 274. 



Hob. On rocks in pools left by the tide, most abundant 

 near high water mark. Berwick Bay. 



From 6 to 12 inches long, as thick as a goose-quill, of a soft 

 consistence, being gelatinous internally. It imparts to 

 fresh water a copious pink dye, and is apt to stain the pa- 

 per, to which it adheres very closely, of the same colour. 



" Bambergae Northumbrise cum essem, narrarunt mihi (Rajo) 

 piscatores speciem quandam Algae tinctoriae in mari oram 

 alluente copiose provenire, quae piscium etiam transna- 

 tantium tergora colore suo inficiat. Plantam ipsam non 

 vidimus, sea ex eorum relatione algae tinctoriae J. B. affi- 

 nem esse suspicabamur." HAII Syn. i. 51. Our fisher- 

 men of the present day have no such tales to tell. 



152. CHORDA. 



1. C. Filum, frond olive-green, cartilaginous, much elongated, 

 attenuated at each extremity, the transverse septa not accompa- 

 nied by external constriction GREV. Alg. Brit. 47* Fucus Filum, 

 LIGHTF. Scot. 963. WITH. iv. 120. NEILL in Edin. Encycl. x. 

 19. Chordaria Filum, HOOK. Scot. ii. 98. Scytosiphon filum, GREV. 

 FL Edin. 288. 



Hob. Common on the coast. In the bay of Holy Island 

 it attains a great length, 20 feet at least, waving under 

 the water like long strings, and generally terminated 

 with a tuft of parasitical confervae. Summer. 



This cordlike sea-weed is hollow, but the cavity is interrupt- 

 ed at short intervals by transverse partitions, the use of 

 which, according to Colonel STACKHOUSE, is to confine the 

 air or elastic vapour to certain spaces, so as to increase the 

 buoyancy of a plant which extends itself to an amazing 

 length, and always shoots upwards to the surface. 

 " The stalks skinn'd when half dry, and twisted, acquire 

 so considerable a degree of strength and toughness, that 

 we are informed the Highlanders sometimes used them 

 for the same intentions as Indian-grass." LIGHTFOOT. 

 In Orkney it is accounted excellent for making kelp suited 

 to the manufacture of soap. 



