Dr. Greville on some new species of Sargassum. 205 



main branches nearly as large as a small garden-pea ; those on 

 the ramuli considerably smaller and subpyriform. Receptacles 

 cylindraceous, forming a subdichotomously divided axillary ra- 

 ceme of an inch or more in length, on the lower part of which are 

 generally found several vesicles and minute leaves, the latter pre- 

 serving all the characters of the larger ones ; the divisions of the 

 raceme are conspicuously divaricate, and even the extreme apices 

 often terminate in a minute wide-spreading fork, as in some 

 species of Cladonia. Substance of the whole plant between 

 cartilaginous and membranaceous, somewhat translucent. Colour 

 in the dried specimens pale olivaceous brown. 



This beautiful species is probably very variable in its secondary 

 characters, and a larger series than I have seen would be re- 

 quired before it could be satisfactorily described. Young plants 

 before the fructification is fully developed might almost be taken 

 for another species. 



This was also communicated by Professor Henslow. 



3. Sargassum ornatum (nob.) ; ramis teretiusculis ; foliis oblongo- 

 obovatis, costatis, repando- dentatis, membranaceis, petiolatis ; 

 vesiculis subsphsericis ; receptaculis cylindraceis, obtusis, race- 

 mosis. 



Hab. in mare Chinensi } 



Root unknown. The whole plant is probably upwards of two 

 feet in length, but the only specimen I have seen is sixteen inches 

 long, slender, producing branches towards the base, four or five 

 inches in length, at intervals of about an inch, and becoming 

 gradually shorter upwards. On these branches are situated the 

 very short ramuli, which, besides the accompanying leaf, consist 

 of nothing more in general than a vesicle or two and the raceme 

 of fructification. Leaves one to near two inches long, the larger 

 ones above half an inch broad, oblong-obovate, rounded at the 

 extremity, attenuated at the base into a slender stalk, irregularly 

 and unequally repando-denticulate, thin and translucent, the 

 midrib slender, disappearing beneath the apex, the pores minute 

 and scattered. Vesicles nearly spherical, the largest about the 

 size of a small garden-pea, rarely mucronate or marginate, the 

 stalk filiform, about two lines long ; those which often form a 

 part of the raceme, somewhat pyriform. Receptacles axillary, 

 cylindraceous, obtuse, forming an irregularly divided raceme 

 3-5 lines in length. Substance thin and membranaceous, and on 

 being remoistened, very flaccid. Colour pale yellowish or oliva- 

 ceous brown. 



A very elegant species, native I believe of the Chinese Seas ; 

 but I regret that my note regarding it has been mislaid. 



