GRIFFITHSIA. 167 



short, of the ramuli once and half as long as broad. Harv. 

 Phyc. Brit. t. xlvi. ; Harv. in Hook. Br. Fl. ii. p. 337 ; 

 Wyatt, Alg. Danm. No. 88. Cow/. Griffithsiana, E. Bot. t. 

 2312. 



On rocks between tide-marks. Southern shores of England. Holy- 

 head, Mr. Ralfs. Stems tufted, many rising from a broadly expanded disk, 

 thick, 2 8 inches high, irregularly branched, cartilaginous, densely cellu- 

 lar, with an obscure appearance of articulation ; branches beset with short, 

 hair-like, simple or subdivided, scattered ramuli. Colour a dull red, fad- 

 ing to brownish. A curious plant, and extensively distributed over the 

 world. It is found in the Indian and Pacific Oceans, and in the Mediter- 

 ranean. 



V. GRIFFITHSIA. Ag. [Plate 23, B.] 



Frond rose-red, filamentous; filaments articulated through- 

 out, mostly dichotomous; ramuli single-tubed, often whorled; 

 dissepiments hyaline. Fructification double : 1, roundish, 

 gelatinous, involucrated receptacles (favellts], including mi- 

 nute granules ; 2, tetraspores affixed to whorled ramelli. 

 Named in honour of Mrs. Griffiths, of Torquay, Devonshire, 

 the "facile Regina " of British algologists. 



* Branches set with short ramelli. 



1. G. equisetifolia, Lightf. ; stems robust, cartilaginous, 

 whorled throughout with closely imbricated, incurved, many 

 times dichotomous ramelli. Hook. Br. Fl. ii. p. 337 ; Wyatt, 

 Ala. Danm. No. 181 ; Harv. Phyc. Brit. t. Ixvii. Conf. 

 equisetifolia, E. Bot. t. 1479. 



On the shores of England and the west of Ireland. Frequent. Bare 

 in Scotland. Frith of Forth, very rare, Mr. Yalden. Perennial. Sum- 

 mer. Stems 3 8 inches high, a quarter of a line to nearly a line in dia- 

 meter, inarticulate, much and irregularly branched ; the chief divisions 

 more or less beset with shorter branches, of half an inch to an inch in 

 length, simple, and (including their ramelli) fusiform, tapering to the apex 

 and base ; the whole frond beset at distances of about half a line with 

 incurved, dichotomous, jointed ramelli, about a line long and overlapping 

 each other. The joints of these ramelli about 4 times as long as broad, 

 swollen upwards. Colour a fine rose-red, sometimes brownish. The fruc- 

 tification remains imperfectly known. 



2. G. simplicifilum, Ag. ; stems slender, irregularly 

 branched, whorled with imbricated, straight, once-forked ra- 

 melli. Harv. in Mack. Fl. Hib. pt. iii. p. 212 ; Harv. Phyc. 

 Brit. t. cclxxxvii. 



