286 Marine Algce of Berwick-on- Tweed. 



Syn. Cladostephus verfcicillatus, J. Ag., Spec. Alg. i„ p. 43 ; Le JoL, 

 Liste, p. 81 ; Pringsheim, Sphacelarien Reihe, pi. I., et seq. 

 Cladostephus myriophyllum, Ag., Syst., p. 169 ; Ktz., Spec. Alg., 



p. 468. 

 Conferva myriophyllum, Both, Cat. Bot. nr., p. 312, t. 12, fig. b. 

 (1806). 

 Hab. On rocks and stones near low-water mark. Coves, Holy Island. 

 Very rare. 



Family— R alfsiaceee. 



RALFSIA, Berk. 



Subgenus— EUR ALFSI A. 



Ralfsia verrucosa, Aresch. 



Linn. (1843) p. 264. 

 ^ Descr. Ralfsia verrucosa, Furlow, Mar. Alg. New Eng., p. 87. 



Fig. ,, ,, Farlow, I.e. pi. v. fig. 5 ; Rice., Atlas Deutsch. 



Meeresalg. t. vi. ; Tab. Nostr. x., fig. 8. 

 Exsicc. ,, ,, Le Jol., Alg. Mar. Cherb., no. 37. 



Syn. ,, „ J. Ag., Spec. Alg. i., p. 62. 



Ralfsia densta, Berk., in Eng. Bot. Suppl. t. 2866 ; Harv., Phyc. 

 Brit. pi. 98; Ktz., Spec. Alg., p. 544 (partim) ; (non Ralfsia 

 deusta J. Ag.) 

 Zouaria (?) deusta, Ag., Syn., p. 40; Johnston, PI. Berwk. n., 

 p. 248. 

 Hub. On rocks in pools from high-water mark to half-tide level. All 

 the year. Fruit Dec. — March. Common. Berwick Bay, 

 Holy Island, Scremerston, and elsewhere along the coast. 

 This curious plant, which, to the naked eye, has more the 

 appearance of a crustaceous lichen than an Algse, forms coriaceous 

 expansions, often of considerable size, on rocks near high- water 

 mark. 



The unilocular sporangia are produced in abundance during 

 the winter months, they are obovate "035 — '040 mm. long by 

 •018 or 019 m.m. broad, and are accompanied by clavate 

 paraphyses. The plurilocular sporangia on the other hand are 

 very rarely met with, and are not accompanied by paraphyses. 

 They are formed from the vertical filaments of the thallus, and 

 are composed of many cells, sometimes longitudinally divided 

 into two parts, "007 or *008 mm. broad, ranged in filaments 

 which are closely packed together so as to form indefinite sori on 

 the surface of the fronds (vide Plate x., fig. 8). 



