Br. Greville on some new species of Sargassum. 203 



fourth is much shorter than the third ; the fifth is shorter than 

 the fourth ; the sixth is not half the length of the fifth ; the 

 seventh is thrice the length of the sixth : the front is narrow and 

 slightly concave : the eyes are remarkably bright red : the mouth 

 is yellow ; its tip is black : the nectaries are black, and between 

 one-seventh and one-eighth of the length of the body : the tip of 

 the abdomen is hairy, dark green, long and curved : the legs are 

 hairy, long and black ; the base of the thighs is pale green ; the 

 fore-thighs and the middle thighs are blackish green ; their tips 

 are black; the shanks and the second joints of the feet are 

 slightly curved. One individual had pale green hind-feet, and 

 one of its hind-shanks excepting the base was of the same colour. 

 When it has shed its skin all its limbs are white, and the colour 

 of the body is fresh pale green without any white bloom. 



The viviparous winged female. This does not much differ from 

 the winged insect, but the disc of the head, the chest, and the 

 breast are pale brown : the wings are colourless, and a little 

 longer than the body ; the wing-ribs and the rib-veins are pale 

 green ; the brands and the other veins are tawny. 



Length of the body l|-2 lines ; of the wings 3-3i lines. 



[To be continued.] 



XXIII. — Alga Orientates : — Descriptions of new Species belonging 

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



[With a Plate.] 



VACHELLIANiE. 



1. Sargassum Henslowii (nob.) ; caule compresso, ramosissimo ; foliis 

 cartilagineis, ecostatis, cuneatis, subdentatis, superioribus versus 

 apicem oblique excavatis, acute dentatis ; vesiculis oblongo-ellip- 

 ticis, apiculatis ; receptaculis minutis, cylindraceis, subpaniculatis. 



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



Whole plant three or four feet long, slender, but at the same 

 time bushy from the numerous secondary branches. Root un- 

 known. Stem not thicker than a crow-quill, compressed, giving 

 off branches at intervals of 1-2 inches, some of which are a foot 

 or more in length ; secondary branches 1-3 inches long, thickly 

 clothed with very short tufted ramuli, bearing the fructification. 

 Leaves ; on the main stem an inch or more long, of a thickish 

 and somewhat opake substance, spathulate or cuneate, much at- 



* Read before the Botanical Society of Edinburgh, July 13, 1848. 



14* 



