234 Marine Alger, of Berwick-on-Tweed. 



Family — N ostochinese. 

 Tribe I.—USCILLARIEjE. 

 SPIRULHSTA, Turpin. 



SPIRULINA TKNU1SSIMA, Kt%. 



Phye. gen., p. 183. 

 Descr. Spirulina tenuissima, Hare, Phvo. Brit. : Farlow, Mar. Alg. New 



Eng., p. 31. 

 Figs. „ „ Rarv.. I.e. pi. 105, fig. 0. : Farlow, I.e. pi. 



ii., fig. 4 ; Ktz., Tab. Phyc. I., pi. 36, fig. 4. 

 Hob. On the muddy bottoms of tide-pools near high-water mark. 



Sept. -Jan. Rare. Ranks of Hie Tweed above the old bridge. 



SPIRULINA PSEIJ.DO-TENUISSIMA, Crouatl. 



Mem. Soc. Sc. Nat. Cherb., vol. n. 

 Descr. e.t Fig. Spirulina psendo-tennissima. Crouan, Flor. dn Finisr., p. 



112, pi. 2. fig. 15. 

 Exuicc. Spirulina tenuissima. Crn., Alg. Mar. Pinist. Exsic. 323. (Non 



Ktz., Spec.) 

 Hah. On the muddy bottoms of the shallow pools of brackish water 

 left by the reeeding tide along the banks of the Tweed above 

 the Railway bridge. Sept. Very rare. 

 This species forms thin, emerald-green patches on the mnd in 

 tide-pools, eventual!}- it rises to the surface of the water in little 

 flakes. The filaments are more slender, and not so closely cnileu 

 as those of S. tenuissima. 



OSCILLARIA, Ktz. 



Oscillaria littoralis, Crouan, 



Flor. du Finist. p.'ll3 fBxcl. syn. 

 Exsicc. Oscillaria littoralis. Crn., Alg. Mar. Finist.. no. 325. 

 Hob. Forming a slimy dark green stratum on the mud along tin- 

 banks of the Tweed and at Fenham Flats. July- Oct. Nol 

 uncommon. 

 I am indebted for the identification of this and most of the 

 other species of OsnlUria mentioned in this list to M. Gomont. 

 He considers my specimens belong to the same species as those 

 distributed by Crouan in his fasciculi under the name of 

 Oscillaria littoralis. Crouan's plant, however, is not identical with 

 the Oseillatoria littoralis, Carm., of Phycologia Britannica, but as 

 Dr. Farlow has pointed out (Mar. Alg. New Eng., p. 33) is nearly 

 related to Oscillaria limosa. Ktz., vnr. rhalybea. 



