226 CRYPTOGAMIA ALGvE. 



936. WITH. iv. 106. Phasgenon Columba, WALKER'S Essays, 

 186. 



Hab. Shores of the Holy Island, in deep water. 7/ 



* * * Frond ribless, undivided. 



4. L. saccharina, stalk cylindrical, short, expanding into a car- 

 tilaginous olive-brown linear or linear-oblong frond, smooth or 

 puckered, with waved margins. (Sea Belts.) HOOK. Scot. ii. 98. 

 GREV. Alg. Brit. 32. Fucus saccharinus, L.IGHTF. Scot. 940. 

 WITH. iv. 105. NEILL in Edin. Encycl. x. 20. 



Hab. Coast of Berwickshire near low-water mark, com- 

 mon. If 



" This common species, which grows to the length of 6 or 7 

 feet, derives its specific name from its being, after it is 

 steeped in fresh water and exposed to the sun, covered 

 with a white efflorescence resembling sugar, but nauseous 

 to the taste. It is not the c saccharine fucus' of the Ice- 

 landers, as has been generally supposed." HOOKER. 

 " When dry, and suspended in an airy place, it forms an 

 admirable hygrometer, and preserves its qualities for 

 years." STACKHOUSE. 



L. saccharina and digitata have been observed to renew their 

 fronds in a very curious manner. A new frond proceeds 

 from the top of the stalk, and gradually pushes before it 

 the old one after this has discharged its office, a deep con- 

 traction marking the place of separation between the two. 

 The phenomenon is not of unfrequent occurrence. 



5. L. phyliitis, stalk cylindrical, compressed upwards, passing 

 into a thin, membranaceous linear-lanceolate frond, tapered to- 

 wards each end, pale yellowish-brown, smooth, the margins wavy. 

 GREV. Alg. Brit. 34. Fucus phyllitis, WITH. iv. 109. 



Hab. Coast of Berwickshire, rare. 



Some excellent observers suppose this to be the young of the 

 preceding, or a variety produced by local causes, and they 

 are probably right ; yet when recent specimens of equal 

 size are compared, the difference in firmness, thickness, 

 and colour, is obvious enough. 



129. HALYMENIA. 

 i. //. Brodiai, stem cylindrical, filiform, somewhat dichoto- 



