THE MARINE AJ.GM OF NEW ENGLAND. 103 



SAEGASSUM, Ag. 



(From 8argazo, the Spanish name for the gulf-weed) 



Fronds attached by a disk having branching stems, leaves with a 



midrib and distinctly stalked air-bladders; fruit in special compound 



branches; conceptacles hermaphrodite; spores single in the mother-cell. 



The most highly organized and by far the largest genus of the Fucacew, of which at 

 least 150 species have been described. They inhabit the warmer waters of the globe, 

 where they replace the Futi. Australia, Japan, and the adjacent coast of Asia are 

 particularly rich in species. We have one species which does not come north of Cape 

 Cod, but which is common southward. The genus has been subdivided by Kiitzing, 

 but even with his limitation the species of Sargassum are very numerous. 



S. vulgare, Ag. (Fucus naians, Turner's Hist. Fuc., PI. 46, non 

 Linn.— 8. vulgare, Phyc. Brit., PI. 343.) 



Fronds two to five feet long, stem filiform, smooth, irregularly 

 branching, leaves shortly petiolate, linear-lanceolate or oblong-lanceo- 

 late, one to three inches long, a quarter to half an inch wide, sharply 

 serrate, midrib distinct, cryptostomata numerous on both sides of the 

 midrib ; air-bladders spherical, quarter of an inch in diameter, stalked, 

 arising from a transformed leaf, the upper part of which often remains 

 as an appendage; stalks naked or slightly winged ; receptacles filiform, 

 branching cymosely, one to two inches long. 



Var. Montagnei. (8. Montagnei, Bailey, in Ner. Am. Bor., Yol. I, 

 PI. 1 a.) 



Leaves narrowly linear, elongated, receptacles two to four inches long. 



Below low- water mark in warm, shallow bays from Cape Cod south- 

 ward. 



In spite of its variations, with the exception of 8. baeciferum, which is sometimes 

 washed ashore, we have but one species of Sargassum on our coast. As usually found, 

 it is more slender in all its parts than the typical S. vulgare of the West Indies, but it 

 is occasionally found of the typical form. In var. Montagnei, which is common, we 

 have an extreme form, in which the fructifying branches are much elongated, but one 

 sees all variations from short to long. 



S. BACcrFERUM, Ag. — Gulf-weed. (Fucus natans, L.; Turner's Hist. 

 Fuc, PI. 47.— & baeciferum, Phyc. Brit., PI. 109.) 



Fronds six inches to a foot and a half long, stems filiform, smooth, 

 leaves linear-lanceolate, two to four inches long, midrib distinct, crypto- 

 stomata usually wanting ; air-bladders stalked, spherical, tipped with a 

 filiform point ; receptacles short, cylindrical, forked. 



Washed ashore at Bath, L. I., Mr. A. E. Young, and found floating off 

 the coast near the Gulf Stream; West Indies, and floating in the 

 Atlantic. 



The common Gulf-weed, which grows attached in the West Indies, where it fruits, 



