IV. FUCACEJ^.— Saegasstbi. 59 



sometimes remotely dentate or merely repand, delicately membranaceous, of a very 

 pale greenish olive colour, minutely glandular, furnished with a percurrent midrib. 

 Air-vessels globose or slightly oval, on slender, square stalks, tipped either with a 

 long filiform point or with a linear-lanceolate leaf, either of which is often deciduous. 

 Receptacles axillary, filiform, tubercular, more or less forked, sometimes attenuate. 

 Colour pale. Substance delicate. 



My specimens, from which the plate has been drawn, were gathered in August, 

 when many of them had formed receptacles. The fruit figured is scarcely mature. 

 The receptacles eventually become more filiform, and repeatedly forked. I have 

 received from Professor Bailey a fragment of a fertile branch of a Sargassum, destitute 

 of leaves and therefore doubtful, but which probably belongs to this species, In it the 

 receptacles are very much lengthened, slender, tassel-like, an inch and half long and 

 repeatedly forked, and have something the aspect of the fructification of Lycopodium 

 Phlegmaria. Should future observations on the spot, made later in the season, 

 show that these very long receptacles are the ordinary state of the ripe fruit, it 

 will materially strengthen the specific character. Professor J. Agardh mentions a 

 var. of S. vulgare, which he calls trichocarpum, distinguished by similar tassel-like 

 fruit. This species is dedicated by Professor Bailey to our mutual friend and 

 fellow student. Dr. Montague, of Paris. The S. vulgare var. tenuifolium of Mr. 

 Obiey's list ought, at least in part, to be referred to S. Montagnei. 



3. Sargassum affi,ne, J. Ag. ; " stem filiform, smooth, leaves lanceolate-linear, 

 acutely serrate, with a single row of glandular pores at each side of the midrib ; 

 air-vessels spherical, pointless, on subterete stalks of their own length ; receptacles 

 axillary, forked, racemose, cylindraceo-lanceolate, warted, unarmed." J. Ag. Sp. 

 Alg. vol. \.p. 343. 



Hab. In the West Indian Sea. J. Agardh. (v. s. in Herb. Trin. Coll. Dublin.) 



I introduce this, as it may probably be found on some of the Florida Keys. It 

 seems to be intermediate in character between S. vulgare and S. bacciferum. 



4. Sargassum bacciferum, Ag. ; stem filiform, smooth ; leaves linear-lanceolate, 

 attenuate, sharply serrate, ribbed, usually destitute of glandular pores ; air-vessels 

 on subterete stalks, spherical, tipped with a filiform point ; receptacles axillary, 

 forked, cylindrical, warted, unarmed. /. Ag. Sp. Alg. vol. 1. p. 344; Kiits. Sp. 

 Alg. p. 609; Rarv. Phyc. Brit. t. 104. Fucus bacciferus, Turn. Hist. Fuc. t. 47. 



Hab. Floating in the Gulf-stream, and thrown up abundantly on the Florida 

 Keys, and on other parts of the coast, (v. v.) 



The floating fronds generally grow from a central point, from which branches 



