216 Dr. Greville on some neiv species of Sargassura. 



ture and in the deep punctures on the elytra it is allied to Man- 

 nerheimii, but is a larger and more robust insect ; the thorax 

 especially is much larger and broader at its basis. 



I captured three specimens near Dorchester in May 1848, a 

 pair of which I gave to Dr. Schaum, who informed me by letter 

 after his return to Germany, that the species is unknown on the 

 continent. 



Ramsgate, Febiuaiy 15, 1849. 



XXIV. — AlgcE Orientales : — Descriptions of new Species belonging 

 to the genus Sargassum. By R. K. Greville, LL.D. &c.* 



[Continued from p. 109.] 

 [With a Plate.] 



WlGHTJAN^. 



13. Sargassum obovatum (nob.); caule subcompresso ; foliis cauli- 

 nis obovatis, obtusissimis, subintegris vel obcure dentatis ; abis 

 racemis intermixtis lanceolatis, seiratis ; vesiculis subelbpticis ; 

 receptacubs minutis, oblongis, c}dindraceis, in racemis densis, 

 rotundatis, pedunculatis, aggregatis. 



Hab. in marl Peninsulce Indise Orientabs ; Wight. 



Root unknown. Plant probably 1-2 feet long, judging from 

 the fragment in my possession, which is apparently a portion of 

 one of the primary branches or divisions of the stem ; this is 

 somewhat compressed, as thick as a blackbird^s quill, beset with 

 numerous branches 2-3 inches long, which are bushy with ramuli 

 less than an inch in length on which are found the racemes of 

 fructification. Leaves : those on the stem above an inch long, 

 obovate, quite rounded at the extremity, almost entire or ob- 

 scurely repando-dentate, furnished with a nerve which disappears 

 at some distance from the end ; those on the smaller branches 

 often more or less serrated, while those which accompany the 

 fructification ai-e much smaller, linear-lanceolate, and sharply ser- 

 rate. Vesicles attaining the size of a small garden pea, varying in 

 shape from elliptical to spherical, sometimes apiculate, supported 

 on a compressed stalk generally little more than a line in length. 

 Sometimes, however, one of the little lanceolate leaves becomes 

 converted into a vesicle, and the stalk is then proportionally 

 long. Receptacles cylindraceous, oblong, much-divided and lobed, 

 forming a dense, roundish, very shortly pedicellated cluster a line 

 or more in length. Colour very dark red-broAvn. Substance 

 thick and cartilaginous. 



* Read before the Botanical Society of Edinburgh 11th Jan. 1849. 



