Marine Algae of Berwick-on-Tiueed. 285 



special branches arising from the cortical layer of the main axis, 

 as is the case in the genus Cladostephus. Both kinds of fruit are 

 shortly pedicellate, and mostly secund on the upper side of the 

 fruit-bearing branches, the unilocular sporangin are globose, the 

 plurilocular sporangia oblong ovate. The fruit-bearing branches 

 are usually very numerous, and form a sort of plush around the 

 denuded portions of the main stems, just below the point where 

 the pinnae commence. 



The pinnae are longer and not so closely set as those of 

 Sphacelaria plumigera, and the branches are not so much fascicled 

 above. Sphacelaria plumigera, moreover, nearly always grows 

 between tide-marks, while Chcetopteris plumosa is an inhabitant 

 of the deep water beyond the influence of the tides. 



CLADOSTEPHUS, Ag. 



Cladostephus spongiosum (Lightf.) Ag. 



Syst., p. 168. — Conferva spongiosa, Light/., Fl. Scot., 

 p. 983. 

 Debcr. Cladostephus spongiosum, Harv., Phyc. Brit. 

 Fig. „ „ Harv., I.e. pi. 138. 



Exsicc. „ ,, Wyatt, Alg. Danm., no. 169; Le Jol., 



Alg. Mar. Cherb., no. 146; Crouan, Alg. Finist., no. 43. 

 Syn. Cladostephus spongiosus, J. 0. Ag., Spec. Alg. i., p. 43 ; Ktz., Spec. 

 Alg., p. 469 ; Johnat., Fl. Berwk. n., p. 245. 

 Cladostephus verticillatus, var. spongiosus, Farlow, Mar. Alg. 



New Eng., p. 78. 

 Conferva spongiosa, Dillw., Syn., p. 76, t. 42; Eng. Bot. t. 2427. 

 Cladostephus laxus, Fl. Dan., t. 1955 (?) excl. Syn. 

 Hab. On sand-covered rocks from half -tide level to low- water mark. 

 All the year. Fruit Jan. and Feb.. Common. Berwick Bay, 

 Burnmouth, Holy Island, and elsewhere along the coast. 



Cladostephus verticillatus (Lightf.) Ag. 



Syn. Int., p. xxv. — Conferva verticillata, Light/., Fl. Scot., 

 p. 984(1777). 

 Descr. Cladostephus verticillatus, Harv., Phyc. Brit. 

 Fig. „ ,, Harv., I.e. pi. 33. 



Exsicc. ,, „ Wyatt, Alg. Danm., no. 82; Le Jol., 



Alg. Mar. Cherb., no. 48; Crouan, Alg. Finist., no. 44. 



