536 Notes on the Marine Algce of Berwick-on-Tweed. 



This plant grows in little tufts of a bright green colour, cover- 

 ing whatever it grows on with its minute fronds. The intercalary 

 heterocysts are a great guide to its identification. It was found 

 at Salcombe near Teignroouth by the late Eev. E. Cresswell in 

 1880, and was then new to Britain. 



The Grreenses Harbour, on rocks and Ralfsia verrucosa. Very 

 rare. 



5. Calothrix puhinata, Ag. (C. hydnoides, Sarv). 

 Bummouth; "Greenses," Scremerston, &c. Eare. 



6. Cladophora arctiuscula. {Kutz.) Cm. Alg. Mar. Finist. No. 

 376. Desmaz, Exs. No. 475. Conferva arctiuscula, Cm. Fl. 

 Finist. p. 127. Cm. MS. Spongomorpha arctiuscula. Kg., Tab. 

 Phyc. IV. pi. 75. 



Caves near the Needle's Eye and further northward. Eare. 



This species resembles a miniature form of Clad, arcta, but 

 forms a continuous cushion over the rock and does not appear 

 ever to grow in tufts like the other species of the genus. Crouan 

 remarks (Fl. de Finst., p. 127) that when growing it has the 

 appearance of a Vaueheria. This plant which has also been found 

 at Dunbar and Joppa is new to Britain. 



7. Codiolum longipes. Foslie. 



Scremerston, E. M. Holmes and E. A. L. B. Greenses. 

 E. A. L. B, Very rare. 



This very curious plant forms a velvety coating over rocks, 

 and unless looked for closely may easily be passed over for 

 VTothrix flacca or some species of Calothrix which it much re- 

 sembles to the naked eye. Under the microscope however the 

 oblong fruit head borne on a transparent stalk much longer than 

 the head itself renders its recognition easy. 



The surface of the growing plant is peculiarly soft and velvety 

 to the touch. Berwick specimens exactly correspond in all 

 respects with American specimens of Codiolum longipes kindly 

 sent me by Mr F. Collins of Maiden near Boston, U. S. A., 

 who has also compared our plant with American specimens. If 

 this plant be preserved on fragments of rock, as it grows it fades 

 to a yellowish colour, but if scraped from the rock and set out on 

 paper it keeps its colour to a much greater extent. 



8. TJVca Ralfsii {Karv .) Ze t/b^. Liste des. Alg. Mar. de Cherb. 

 p. 54. Enteromorpha Ealf sii. Harv. Phyc. Brit. pi. 282. Le Jol. 

 Alg. Mar. Cherb., No. 230. 



