106 BRITISH SEA-WEEDS, 



This very pretty plant was discovered at Torquay in 

 1837 by the distinguished algologist whose name it 

 bears. It has since been found in one or two other lo- 

 calities, but must still be considered a great rarity. It 

 grows parasitically on Polyides rotundus and other small 

 algse, between high- and low-water mark. It is annual, 

 and to be found at the end of summer and in early 

 autumn. 



Polysiphonia spintilosa. Round-fruited Poly- 

 siphonia. 



" Dark-red ; branches divaricate, somewhat rigid, the 

 ramuli short, straight, subulate, divaricate; articulations 

 about equal in length and breadth, three-tubed. Tubercles 

 (spore conceptacles) globose, sessile, excessively minute." — 

 Oreville. 



So little is known of this plant, that it is difficult to 

 determine whether it be a distinct species, or merely a 

 variety. The only recorded specimens were found many 

 years since by Captain Carmicbael, at Appin. The 

 above description is copied verbatim from Dr. Greville's 

 ' Scottish Cryptogamic Flora.' 



Polysiphonia Richardsonii. Sir John Richard- 

 son's Polysiphonia. 



" Stems cartilaginous, setaceous ; branches alternate, elon- 

 gated, divaricate, beset in the upper part with very patent, 

 straight, subdichotomous ramuli ; articulations of the stem 

 and branches two or three times longer than broad, irre- 

 gularly veined ; of the ramuli shorter. Capsules sessile, 

 globose." — Harvey, Fhyc. Brit. 



This is another very doubtful species, the only known 



