Dr. Greville on some new species of Sargassum. 255 
narrow-obovate, rounded at the apex, attenuated at the base into 
a slender and rather long footstalk, often nearly entire, but more 
generally repando- or even serrato-dentate, furnished with pores, 
and a nerve which disappears before reaching the summit. Ves?- 
cles nearly the size of hempseed, subspherical, supported on stalks 
scarcely a line long. Receptacles a line or more in length, ax- 
illary, obovate, or oblong, compressed, the margin and apex fur- 
nished with broad sharp teeth; frequently the receptacles are 
proliferous, the whole forming a very irregularly divided raceme, 
which is sometimes so twisted and curled as to give it the appear- 
ance of a cluster of minute proliferous leaves. 
From the two imperfect specimens which I possess of this 
plant, I suspect that it is subject to considerable variation, and 
my figure and description are given chiefly with a view of affording 
algologists a memorandum for its more accurate investigation. 
On one of my specimens several of the leaves are converted into 
vesicles, which are supported on stalks 2 lines long resembling 
the lower part of the leaf; these are also winged and apiculate. 
17. Sargassum divaricatum (nob.) ; caule angulato ; foliis linearibus, 
acuminatis, breviter petiolatis, uninervibus, subintegerrimis ; vesi- 
culis numerosis, sphericis, petiolatis, petiolis planis, dilatatis ; 
receptaculis cylindraceis, filiformibus, divaricato-dichotomis. 
Wight in herb. no. 7. 
Hab. in mari Peninsule Indie Orientalis ; Wight. 
Root I have not seen. Entire plant probably a foot or more 
in length. Stem nearly as thick as a crow-quill, giving off 
spreading branches at short intervals 4 to 6 inches long, which 
are clothed with numerous short ramuli and leaves, so as to give 
the whole plant a bushy appearance. Leaves somewhat more 
than an inch in length, a lme or more broad, more or less 
acuminate, entire, or rarely obscurely subdentate, shortly petio- 
late, furnished with a nerve and pores. Vesicles spherical, smaller 
than hempseed, on little flat dilated petioles about a line long; 
sometimes they are margined, and occasionally on longer stalks 
resembling an abbreviated leaf, and apiculate. Receptacles fili- 
form, cylindraceous, subdichotomously divided, the segments 
spreading, the whole forming axillary tufts, often 3 or 4 lines in 
length. Colour reddish brown, that of the receptacles black. 
Substance cartilaginous. 
A well-marked species, the receptacles separating it at once 
from its congeners. When luxuriant the three or four tufts on 
a ramulus seem to form one mass, and to the naked eye suggest 
the idea of a little parasitic Gigartina, and is by no means unlike 
dwarf specimens of Gymnogongrus Griffithsie, Mart. Sometimes 
the receptacles are less abundant and conspicuous, having fewer 
