108 Dr. Greville on some new species of Sargassum. 



giving off spreading branches 3-4 inches long, at intervals of 

 half an inch, which become gradually shorter upwards, thickly- 

 covered with leaves, vesicles and receptacles. Leaves linear- 

 oblong, or, sometimes, oblong-lanceolate, nearly three-quarters 

 of an inch in length, 2-3 lines broad, obliquely attenuated at 

 the base into a very slender petiole, sharply inciso-dentate, or 

 even laciniate, furnished with a delicate nerve and oval pores. 

 Vesicles numerous, spherical, the largest not half the size of the 

 seed of Lathyrus odoratuSy most of them as small as an ordinary 

 pin's head, often apiculate, and the apiculus excentric, furnished 

 with a few papilliform pores, and supported on a little compressed 

 stalk not a line in length. Receptacles axillary, cylindraceous or 

 subcorapressed, oblong or somewhat club-shaped, sharply tgothed^ 

 and forming little racemose tufts about a line and a half long. 

 Colour dull reddish brown. Substance somewhat membranaceous 

 and slightly diaphanous. 



A very beautiful species. When dry, the laciniate teeth of the 

 leaves give them quite a fringed appearance. 



12. Sargassum hrevifolium (nob.) ; caule teretiusculo, muricato ; 

 foliis parvulis, obovatis, dentatis, uninerviis ; vesiculis minutis, 

 sphsericis ; receptaculis filiformibus, elongatis, racemosis. 



Wight in herb. no. 20. 



Var. |S ; foliis laciniato-dentatis, in petiolo longiore attenuate. An 



species distincta ? 

 Wight in herb. no. 10. 

 Hab. in mari Peninsulse Indiae Orientalis ; Wight. 



Root I have not seen. Stem (or primary branch ?) probably 

 2 feet long or more ; but only fragments are in my possession ; 

 cylindraceous, somewhat muricate. Branches 4 or 5 inches long, 

 thickly clothed with the fructiferous ramuli, which are not more 

 than half an inch in length. Leaves ; those on the main branches 

 I have not seen ; those on the secondary branches, from the axils 

 of which the clusters of receptacles and vesicles arise, are about 

 a third of an inch long, more or less obovate, remotely dentate, 

 rounded at the end, furnished with pores and a nerve which soon 

 becomes rather faint and disappears below the summit. Vesicles 

 spherical, numerous, the size of a large pin's head, having pro- 

 minent pores, supported on filiform stalks half a line in length, 

 and arising from the lower ramifications of the raceme. Recep- 

 tacles numerous, filiform, elongated, forming much-divided ra- 

 cemes from a quarter to half an inch long. The receptacles are 

 not unfrequently foliaceous towards their upper extremity, in 

 which case they resemble linear leaves toothed at the margin, and 

 are furnished with a nerve and pores. Colour reddish black when 

 dry. Substance cartilaginous. 



