'XJ'l Marine Algce of Berwick-on-Tweed. 



Hab. In shallow sandy pools between tide-marks, usually about half -tide 

 level. All the year. Not uncommon. Berwick Bay. Sharper 

 Head. Burnmouth. 



In the present gemis " the unilocular sporangia are formed 

 directly from the cortical cells and cover the surface in dense 

 patches, at maturity projecting above the surface of the frond, 

 whereas in the genus Dictyosiphon they are scattered and im- 

 mersed. In Dictyosiphon, moreover, the growth is from an 

 apical cell, but in Stictyosiphon it is trichothallic, and in the 

 former genus the superficial cells are polygonal and irregularly 

 placed, while in the latter they are quadrate and arranged in 

 regular series.* 



Stictyosiphon tortilis is a rather coarse, dark-coloured species 

 growing in large, entangled tufts. The filaments are much 

 curled and twisted, very irregularly branched, and not unfrequent- 

 ly matted together into rope-like bundles. The plant is very 

 brittle when dry, and does not in the least adhere to paper. 



STicTYOsirHON suB-ARTicuLATUS (Aresch.) Hauck. 



Meeresalg., p. 375. — Phloeospora sub-articulata, Aresch., 

 Bot. Not. 1873, p. 132. 

 Descr. Phloeospora sub-articulata, Aresch., I.e. 



Fig. „ „ Aresch., Obs. Phyc. 3, p. 25, t, 3, p. 2-5. 



JE.csicc. ,, ,, Holmes, Alg. Brit. Bar., no. 19. 



Syn. Dictyosiphon foenicnlaceus, var. B., Aresch., Phyc. Scand. Mar., p. 

 148, t. 5f. 

 Stictyosiphon snb-articulatus. Rke., Algenflora der westlichen 

 Ostsee, p. 55. 

 Hab. In shallow sandy pools between tide-marks. Jan. — Nov. Bare. 



Berwick Bay, Sharper Head. 

 The transverse lines seen on tlie fronds under a good lens 

 distinguish this species at sight from Dictyosiphon foenicnlaceus, 

 which it otherwise closely resembles. The habit of the plant, 

 however, is stiffer and the branches and ramuli more appressed. 

 Like Stictyosiphon tortilis it does not adhere to paper, and is very 

 brittle and easily broken when dry. 



* Farlow, Mar. Alg. New Eno-., jn. 6(3. 



