5 1 BTKOP8I8 OF BRITISH SEAWEEDS. 



Conferva fasca, Hnds. 



Wales and south of England. On rock- ai 

 fcween tide-marks. Very rare. 

 Dillwyn, on whose authority the Sphacelaria J 



chiefly rests, gives several stations for it, on the coast of 

 Wales, where it would seem to be pretty common. But 

 except a single specimen sent to me several years ago by 

 Mrs. Griffiths, and another more recently received from 

 Mr. Kalfs, I have seen nothing of the plant; nor am I 

 aware of any other author having found it. As a species, 

 S.fusca (or what I take for it) diifers from S. cirrhosa by 

 its irregular branching, by the remarkable cruciform scat- 

 tered ramuli, and something in colour and in the length of 

 the joints. S. cirrhosa is parasitical on other Algae ; but 

 too little is yet known of the history of S.fusca to say that 

 it is not so. ISo foreign author appears to be acquainted 

 with the plant. 



78. radicans (The rooting Sphacelaria) ; filaments erect, or de- 



cumbent, sending out a few fibrous radicles from the lower 

 part, sparingly branched ; branches alternate, simple, very 

 erect, straight, bare of ramuli ; utricles clustered, » 

 globose, Harv. in Hook. Br. Fl. v. 2. p. 324. (Atlas, 

 PL XVIII. Fig. 79.) 

 Sphacelaria olivacea, Ag. Conferva radicans, Dillw. C. olivacea, 



Dillw. 

 Hah. North of Scotland and Ireland. On sand-covered rocks, 

 between tide-marks. Perennial ? Autumn. Rare. 

 A minute species, one of the least developed of the 

 genuine members of the genus, and more remarkable for 

 its rarity than its beauty. Specimens slightly differing in 

 character, gathered in Orkney by Messrs. Hooker and 

 Borrer, have received the name of olivacea : and thus two 

 species have generally been recognized. A careful com- 

 parison of the characters attributed to each, with an exa- 

 mination of specimens from different localities, has satisfied 

 me that the differences do not warrant the retention of two 

 species, and I consequently unite the S. olivacea of authors 

 to the older S. radicans. The form to which the name 

 olivacea was given is rather more erect, and less disposed 

 to throw out radicles than common ; but there are no other 

 characters by which it can be distinguished. The species 

 was first described in the Appendix to Dillwyn's Conferva. 



79. racemosa {The clustered Sphacelaria) ; " an inch in height, 



