BOSTRYCHIA. 79 



lengthened into branches 6 14 inches long, and clothed at short distances 

 with broad tufts of rnultifid ramuli, resembling those usually borne by the 

 main stem. Some of these specimens seem almost intermediate with R. 

 subfusca, and strikingly resemble Polysiphonia Broduei on a large scale. 

 Fructification is plentifully produced by the summer ramuli. Substance 

 cartilaginous, the summer branches adhering to paper. Colour purplish 

 brown, becoming black in drying. 



2. R. subfusca, Woodw. ; frond filiform, much and irregu- 

 larly branched ; branches virgate, set with scattered, subu- 

 late, simple or pinnulated, alternate branchlets, often crowded 

 towards the end of the branches. Grev. Alg. Brit. p. 103 ; 

 Hook. Br. Fl. ii. p. 294; Harv. Phyc. Brit. t. cclxiv. ; 

 Wyatt, Alg. Danm. No. 111. Fucus subfuscus, Woodw.; 

 E. Bot. t. 1164. 



In the sea, on rocks and Algae. Perennial. Summer. Frequent. 

 Stem 4 10 inches high, undivided or branched, set throughout with nu- 

 merous, alternate, long branches, which bear a second or third series of al- 

 ternately multifid ramuli. In winter these finely divided branches drop 

 off, leaving the frond with the stunted remains of its branches rigid and 

 broken ; but early in the following spring a second series of ramuli arises 

 from the branches, and on these the fructification is produced. Substance 

 rigid in winter, cartilaginous and rather flaccid in summer, when the frond 

 adheres to paper. Colour reddish or brownish, becoming darker in drying. 

 An extremely variable plant in ramification, and in its summer and winter 

 states presenting a startling contrast. 



III. BOSTRYCHIA. Mont. [Plate 11, C.] 



Frond dull purple, filiform, much branched, inarticulate, 

 dotted ; traversed by a jointed tube surrounded by one or 

 more concentric layers of oblong coloured cells, which are 

 gradually shorter towards the circumference ; the surface 

 cells cubical. Fructification twofold, on distinct plants ; 1, 

 ceramidia ; 2, tetraspores, contained in terminal, lanceolate 

 pods. Name, Qorrpw;, a ringlet or curl of hair. 



1. B. scorpioides, Gm. ; frond cylindrical, slender, attenua- 

 ted, three or four times pinnated with horizontal branches, 

 the uppermost involute at the extremity. Grev. Alg. Brit. 

 p. 105; Hook. Br. Fl. ii. p. 294; Wyatt, Alg. Danm. No. 

 69 ; Harv. Phyc. Brit. t. xlviii. Fucus amphibius, E. Bot. 

 t. 1428 



On rocks in the sea, or in salt-water ditches. Annual ? Summer. North 

 Wales, Rev. H. Davies. Abundant at Shoreham, growing on Atriplexpor- 

 tulacoides, Mr. Borrer. Mouth of the river Dart, Mrs. Griffiths. Tydd 

 Marsh, Cambridgeshire, Mr. Skrimshire. Shore of Blackwater at Maldon, 

 Mr. E. Forster,jun. Selsea Marshes, Martyn. At Portstewart, North of 

 Ireland, Mr. D. Moore, and elsewhere. Fronds forming entangled tufts, 



