Marine Algce of Berwick-on-Tweed. 281 



patches^ usually more than half buried in the sand, only the tips 

 of the filaments being visible. When detached from the rock 

 the patches separate into small tufts or single threads, and it is 

 then seen that the different plants are held together almost 

 entirely by the sand amongst which they grow. 



The globose sessile bodies figured by Harvey and Traill on 

 Sphacelaria radicans, are not of the same nature as the pedicellate 

 sporangia of the other Sphacelaria. The Zoospores are formed 

 quite differently according to Pringsheim.*" 



The variety olivacea, although it is occasionally met with in 

 shady places between tide-marks, usually grows in caves. The 

 filaments are densely matted together below, and form an in- 

 definitely extended turf, often many yards in extent, which can 

 be cut from its attachment in felted pieces. The sporangia are 

 oval or globose, and borne on short pedicels composed of from 

 one to three cells. I have seen no plurilocular sporangia. 



Sphacelaria racemosa, Grev. 



Scot. Crypt. Fl. vol. n., t. 96. 



Descr. Sphacelaria racemosa, Grev., I.e. et Harv., Phyc. Brit. 



Fig. „ ,, Grev., La Harv., I.e. pi. 349. 



E.csicc. „ „ Holmes, Alg. Brit. Bar., no. 95. 



Syn. „ „ J. G. Ag., Spec. Alg. i., p. 31; Ktz., Spec. 



Alg., p. 466. 



A rare and interesting species which had not been found in fruit 

 since 1821, when in January 1887 I was so fortunate as to find it 

 in good fructification. " This species has, I believe, been only once 

 or twice previously found in fruit — first by Sir John Eichardson, 

 near Granton, in 1821 ; and next by the late Mr Hennedy, 

 in the Clyde, according to Harvey, many years subsequently." f 



The plants usually grow in small pencilled tufts on the bottom 

 and sides of rock pools between tide-marks, but sometimes many 

 plants grow side by side and get buried in the sand which binds 

 them together into cushion-like patch e k s, which, however, fall to 

 pieces when detached from the rock, and the tufted mode of 

 growth is then quite apparent. So far as I have observed, the 

 plants have not the least tendency to become bound together by 



* Pringsheim, Sphacelarien Beihe, p. 172. 



f Holmes, in Trans. Bot. Soc. Edin., vol. xvn., p. 80. In a note Mr 

 Holmes continues : " I have seen Hennedy's specimens, but could find no 

 fruit on them, and doubt if they belong to Sphacelaria racemosa. I should 

 refer them to Sphacelaria radicans, Harv." 

 1 K 



