282 Marine Algai of Benvick-on-Tiveed. 



the rhizoidal filaments, which, although present, are not 

 numerous. 



The filaments are sparingly branched, the branches scattered, 

 irregularly placed, somewhat appressed, the joints about as long 

 as broad, in these respects resembling Sphacelaria radicans, and 

 although Sphacelaria racemosa is taller and decidedly more tufted, 

 barren specimens of the two species could hardly be distinguished. 

 The singular grape-like fructification, however, at once marks 

 the species ; the sporangia are oval or spherical, and are arranged 

 in a racemose manner on special branches crowded together into 

 almost globular clusters, which are visible to the naked eye. 

 The racemes arise from almost any part of the filaments, and are 

 usually very numerous. 



Sphacelaria tribuloides, Menegh. 

 Lett. Corin., p. 2, n. 1. 

 Descr. Sphacelaria tribuloides, J. Ag., Spec. Alg. I., p. 31. 

 Fig. „ „ Ktz., Tab. Phyc. v. t. 89 ; Zan., Icon. 



Phyc. Adr. in., p. 43, tav. 40b. 

 Sijii. Sphacelaria tribuloides, Ktz., Spec. Alg., p. 464; Hauch, Meeres- 

 alg., p. 343. 

 Sphacelaria rigida, Serine/, Ktz., Spec. Alg., p. 465 ; Id., Tab. 

 Phyc. v. t. 90. 

 Hub. In rock pools between tide-marks. Jane — Oct. Very rare. 



Sharper Head. 

 A small plant, forming erect tufts about an inch high. In 

 colour, manner of branching, and habit, it closely resembles the 

 two preceding species, but differs from both of them in. the 

 length of the articulations, which are from once and a half to 

 twice as long as broad. When present, the curious three 

 cornered propagula also serve to mark the species. 



Sphacelaria cirrhosa (Eoth) Ag. 



Syst. Alg., p. 164. — Conferva cirrhosa, Roth, Cat. Bot. n.j 

 p. 214 ; vol. in., p. 294. 

 Descr. Sphacelaria cirrhosa, Harv., Phyc. Brit.; Furlow, Mar. Alg., p. 70. 

 Fig. „ „ Harv., I.e. pi. 178. 



Exsicc. ,, ,, Wyatt, Alg. Danm., no. 171 ; Crouan, Alg. 



Finist., no. 33 ; Le JoL, Alg. Mar. Cherb., no. 39. 

 Syn. Sphacelaria pennata, Lyngb., Hydr. Dan., p. 105, t. 31 (excl. 

 var. b.) 

 Conferva cirrhosa, Hook., Fl. Scot., part 2, p. 86. 

 Conferva pennata, Buds., p. 604 ; B. B. t. 2330 ; Fl. Dan., t. 1486, 

 fig. 2. 



