(56) 



breadth, sometimes nearly linear, at others roundish ovate, five to six 

 feet or more in length, and from two to six inches or more in breadth, 

 slightly thickened in the middle, especially in old specimens, in the 

 manner of an obscure midrib, sometimes smooth, more frequently 

 marked by large transverse or longitudinal wrinkles. Substance sub- 

 membranaceous or coriaceous, more or less adhering to paper. • Colour 

 of the young plant pale brownish or greenish brown, when old dark 

 olive brown, or when very old nearly black or blackish olive. " Fructifi- 

 cation, according to Turner, occupying irregularly shaped spots in the 

 centre of the leaf, from half an inch to an inch in width, and of various 

 lengths, sometimes extending uninten-uptedly throughout the frond, at 

 other times broken without order." — Phyc. Brit. 



A very common species in every tide-pool and sheltered bay on all our 

 shores, never growing, however, where there is any risk of its being left 

 by the tide, but exhibiting its gi'eatest luxuriance perhaps at a depth of 

 one or two fathoms. 



Specimens differ widely in comparative length and breadth, according 

 to the age of the plant as well as the age of the frond ; we have fre- 

 quently seen specimens from two to three feet in length, and scarcely 

 more than an inch in breadth, while a specimen is just now before us 

 not much over two feet in length, but measmring nine inches in breadth 

 a little above the base. Generally too, the base is broad and rounded, 

 but occasionally also we have seen it more or less cimeate or tapering. 

 It is no uncommon thino; to meet with fronds from three to five inches 

 in breadth, and from six to eight or even ten feet in length. 



It does not genei-ally grow in the middle of the rock-pool, except 

 when it is occupied by large stones, but often forms a dense fringe round 

 its margin, extending not uufrequeutly to the middle of the pool. 



EXPLANATION OF PLATE CXLIX. 



Fig. l.—Laininaria saccharina, youug frond, natural size. 

 2. — Section of same. Magnified. 



