90 LAMINARIACE^.— Laminahia. iv. 



1. CosTAEiA Turneri, Grev. ; stipes flat, expanding into a linear-lanceolate five- 

 ribbed lamina. J. Ag. Sp. Alg. vol. 1, p. 139- Kutz. Sp. Alg. 580. Fucus costatus, 

 Turn. Hist. t. 226. 



Hab. On the North West Coast, Mr. Menzies. 



" Frond solitary, rising with a stipe about an inch in length, marked from top to 

 bottom with prominent, nearly parallel strife, cylindrical, and of the size of a 

 crow's quill at its origin, but almost immediately becoming compressed, and soon 

 after flat, gradually expanding, too, as it rises, but so slowly that at the top it is 

 scarcely above a line in diameter ; it here suddenly expands into a single, flat, 

 undivided leaf, a foot and a half or more long, nearly linear, about two inches 

 wide, quite entire, and slightly waved at the margin, at the base attenuated ; the 

 surface marked all over with irregular transverse wrinkles, and having five parallel 

 ribs running through it from top to bottom. Colour a pale, dirty yellow in the 

 stipe, in the leaf olive-brown, and semi-transparent. Substance of the stem woody, 

 of the leaf membranaceous." — Turn. Hist. 4, p. 72. 



2. CosTAEiA Mertensii, J. Ag. ; " stipes flat, expanding into a cordato-ovate five- 

 ribbed lamina." — J. Ag. Sp. Alg. l,p. 142. Costaria Turneri, Post, and Rupr. t. 24. 



Hab. North West Coast, Dr. H. Mertens. 



I think this must be merely a broad leaved form of the last. 



VI. LAMINARIA, Lamour. 



Frond stipitate, coriaceous or membranaceous, flat, ribless, undivided or irregu- 

 larly cleft. Fructification., cloud-like patches of spores, imbedded in the thickened 

 surface of some part of the leafy expansion. 



The plants commonly known as Oarweed, Tangle, Devil's Apron, Riband-weed, 

 Sole-leaiher-kelp, Sfc. belong to this genus, which is more numerous in species, and 

 possessed of a wider geographical range than any other of the Order. With the 

 exception of L. Fascia, which is only a few inches long, they are all jjlants of a large 

 size, varying from three to twelve, or twenty feet in length. They commence to 

 grow about low-water mark, and descend, beyond that limit, to the depth of five 

 to ten fathoms. 



Many are perennial ; the stipe remaining from year to year and the frond falling 

 away. The new frond is developed between the apex of the stipe and the base of 

 tlie old frond, and at first appears like a flattening and widening of the apex of the 



