96 REPORT OF COMMISSIONER OP FISH AND FISHERIES. 



common on the coast of Maine, but much less abundant than other Laminarice. It ia 

 the most easily recognized of our Laminarice, in spite of its great variability in outline. 

 The substance is more tough and leathery than any of our other species and the mar- 

 gin is thick and never wavy. At Eastport it is found in deep pools, but elsewhere it is 

 an inhabitant of deep water. As usually seen washed ashore it resembles one of the 

 digitate forms of Laminaria, for it is usually torn into segments, and not rarely split to 

 the very base. It is at once distinguished from our digitate Laminarice by its uniformly 

 flat stipe, very short root-fibers, and cryptostomata. In most cases the stipe expands 

 very gradually into the blade, but occasionally in old specimens the base is cordate. 

 The fruit is found in the autumn and winter. In the specimens which we have ex. 

 amined the paraphyses were very narrowly club-shaped and colored to the tip, being 

 destitute of the hyaline tip found in Laminaria. 



AGABUM, (Bory) Post. & Bupr. 

 (From agar-agar, a Malayan word referring to some edible sea- weed.) 



Fronds stipitate, attached by a branching root-like base ; lamina per- 

 forated with roundish holes ; stipe prolonged into a midrib ; fruit scat- 

 tered in patches (sori) over the fronds, consisting of club-shaped, one- 

 celled paraphyses and ellipsoidal unilocular sporangia; plurilocular 

 sporangia unknown. 



A genus differing from Laminaria in having the lamina perforated with round holes 

 and furnished with a distinct midrib. It includes four described species, which differ 

 in the size of the perforations, in the shape of the lamina, and tbe prominence of the 

 midrib, characters which an observation of our common species shows to be very vari- 

 able. The species inhabit the Arctic Ocean, the northwestern shore of the Atlantic, 

 and the North Pacific. The New England form, A. Turneri, also occurs in the Pacific 

 extending as far south as Japan, and, on the west coast, A.finibriatum, Harv., considered 

 by Agardh to be the same as Facus pertusus, Mertens, extends as far south as Santa 

 Barbara, Cal. 



A. Turneri, Post. & Bupr. — Sea Colander. (Fucus cribrosus, Mer- 

 tens. — F. agarum, Turner, Hist. Fuc., PI. 75. — Laminaria agarum and L. 

 Boryi, De la Pyl., Flore de Terre-Neuve. — Agarum Turneri, Post. & 

 Bupr., Illustr. Alg., PL 22; Ner. Am. Bor., Vol. I, PL 5.) 



Exs. — Algse Am. Bor., Farlow, Anderson & Eaton, No. 112. 



Base much branched, stipe two inches to a foot long, cylindrical below, 

 flattened above and prolonged into a distinctly marked midrib ; lamina 

 menbranaceous, one to four feet long, ovate-oblong, cordate and much 

 crisped at base, margin wavy; perforations very numerous, orbicular, 

 irregularly scattered with a smooth or wavy margin ; fruit in irregular 

 patches in the central part of the frond; sori .05-6 mm in thickness; 

 paraphyses club-shaped, colored below, expanded and hyaline at the top; 

 sporangia narrow, ellipsoidal, .OSS™ 11 long by .012 mm broad. 



Common from Nahant northward in deep water and at Eastport in 

 pools ; North Pacific. 



One of the curiosities of our marine- flora, which is washed ashore from deep water 

 at the southern limit of its growth, but farther north grows in pools at low-water mark. 



