204 Dr. Greville on some new species of Sargassum. 



tenuated towards the base, with one or two teeth towards the 

 apex, which is more or less obtuse and oblique ; on the branches 

 the leaves are much smaller, more or less broadly lanceolate and 

 acute, with generally a large tooth on one side above the middle, 

 and the substance obliquely excavated as it were from the tooth 

 to the apex. Vesicles 2-3 lines long, elliptical-oblong, with a 

 slender foliaceous mucro, and supported on peduncles less than 

 a line in length. Sometimes the vesicles are slightly margined, 

 and they are, as well as the leaves, sparingly furnished with pores. 

 Those intermixed with the receptacles are scarcely more than a 

 line or a line and a half long. Receptacles not a line long, linear, 

 cylindraceous, rarely single or once divided, but generally form- 

 ing minute panicles or racemes composed of 3-5 receptacles, 

 with one or two vesicles, and often with minute linear-lanceolate 

 leaves. Colour in the dried state dark reddish brown. 



This species was kindly communicated to me by my friend 

 Professor Henslow in 1831, and had been transmitted to him by 

 the Rev. G. H. Vachell, along with other interesting plants from 

 Macao and the adjacent islands. 



2. Sargassum Vachellianum (nob.) ; caule brevissimo, teretiusculo, 

 muricato ; ramis elongatis, planis ; foliis lineari-lanceolatis, sub- 

 membranaceis, repando-dentatis ; vesiculis sphsericis, petiolatis, 

 petiolis compressis dilatatis ; receptaculis cylindraceis, subdicho- 

 tome racemosis. 



Hob. in mari Chinensi, legit G. H. Vachell. 



Plant two to three feet long, of a slender and graceful habit. 

 Root a cartilaginous disc, from which arise several stems about 

 an inch in length, cylindrical, as thick as a crow-quill, rough 

 with the conical bases of former branches. From the summit of 

 the stem are produced one or more main branches, flat, about a line 

 broad, giving off a second series of branches at intervals of 1-2 

 inches, 2-6 inches long, and bearing a numerous series of very 

 short ones with the fructification. Leaves more or less,, linear- 

 lanceolate, repando-denticulate, sometimes almost spinuloso- 

 denticulate, distinctly petiolate ; those arising from the lower part 

 of the primary branches two to near three inches long and nearly 

 half an inch broad, of a firmer and thicker substance than the 

 rest; those on the secondary branches smaller, seldom exceeding 

 two inches in length, and becoming gradually narrower till on 

 the upper parts they are strictly linear and acuminate, being 

 often not more than a line or even less in breadth. Midrib nar- 

 row, disappearing below the apex; pores small and scattered. 

 Vesicles nearly spherical, rarely mucronate, on petioles 2-3 lines 

 long, which are sometimes dilated and foliaceous ; those on the 



