Sek. MELANOSPERME.E. ( 163 ) Fam. ECTOCARPE.E. 



SPHACELAPJA V.ACFMOSA.—Grcv. 



Gen. Char. —Fronds filiform, articulated, dicLotoinously branched ; apices of the branches 

 generally more or less distended, as if the apical cell was enlarged and inflated, 

 containing in its centre a dark granular mass of endochronie. Fi-uctification : 

 "elliptical utricles (or spores) furnished with a limbus, borne on the ramuli." 

 Name from a(pdKe\os, "a gangrene," in allusion to the withered, diseased-like 

 apices of the branches, very characteristic in some of the species. 



Sphacelaria raceviosa. — " An inch in height, tufted, ohvaceous, some- 

 what rigid, the fronds dichotomous ; articulations equal in length and 

 breadth ; capsules oval, racemose, pedunculate {Grev.y — Phyc. Brit. 



Sphacelaria racemosa. — Gi-ev. Scot. Crypt. Fl. vol. ii. t. 96 ; Grev. Fl. Edin. 

 p. 314; Kiltz. Sp. Alg. p. i^^Q ; /. G. Agardh, Sp. Gen. Ahj. vol. i. 

 p. 31 ; Harv. in Ilooh. Br. Fl. vol. ii. p. 325 ; Harv. Man. p. 57 ; 

 Harv. Syn. p. 52 ; Atlas, plate 18, fig. 80. 



Hab. — In tide-pools? Very rare. Frith of Forth, opposite to Caroline Park {Sir 

 John Richardson) ; Frith of Clyde, rather plentiful {Mr. R. Hennedy). 



Geogr. Dist. — Only found as above, and there only once, about the year 1821. 



Description. — " Plants tnfted, about an inch in height, of an olive 

 green or olive brown colour. Frond filiform, somewhat rigid, three to 

 four times dichotomous, the dichotomies acute. Articulations equal in 

 length and breadth, diaphanous to the base ; summits of the branches 

 not sphacelated in my specimens, but somewhat dilated and hj-aline, as 

 in many other specimens, previous to the sphacelation making its appear- 

 ance. Fructification : oval capsules, surrounded by a very naiTow 

 pellucid border, pedicellate and arranged in a racemose mannei-, on a 

 common jointed pedvmcle. Racemes suberect, arising from vai'ious parts 

 of the frond {Grev. Scot. Cryj^t. 1. c.)" — Phyc. Brit. 



In structure, this seems very closely related to the preceding, but the 

 fructification in its arrangement is widely difi'erent, and forms the most 

 essential character of the species. 



We have received specimens under this name, collected on the west 

 coast of Scotland (Curabrse), but as the fructification is wanting, we 

 feel some hesitation in giving the station or trusting to the characters, 

 the more especially as the articulations are more variable in their 

 relative length and breadth than we would be led to suppose from the 

 figure in Phycologia Britcmnica, many of them being rather longer than 



