170 SEIROSPORA. 



vellte) terminating the branches, surrounded by an involucre 

 and containing several clusters of pear-shaped spores com- 

 pacted together ; 2, tetraspores affixed to the ramuli, scat- 

 tered. Name, in honour of Baron von Wrangel, a Swedish 

 naturalist. Nearly related to Griffithsia, from which this 

 genus chiefly differs in having scattered tetraspores. 



1. W. multifida, Huds. ; stems setaceous, pinnate or bi- 

 pinnate, articulated, each joint bearing a pair of opposite, 

 slender, pinnato-multifid, incurved ramelli, or whorled with 

 numerous forked ramelli; joints of the stem many times 

 longer than broad. Harv. Phyc. Brit. t. xxvii. Griffithsia 

 multifida, Hook. Br. Fl. ii. p. 338 ; Wyatt, Alg. Danm. No. 

 43. Conf. multifida, E. Bot. t. 1816 @. pilif era : ramelli 

 very long, sub-simple and hair-like. 



On perpendicular rocks, near low-water mark. Frequent on the south 

 coasts of England. West of Ireland. Belfast Bay, Mr. W. Thompson. 

 Rare in Scotland, Saltcoats, Miss Margaret Landsborough. ft. Torquay, 

 Mrs. Griffiths Stems 4 6 inches long, as thick as bristles, undivided, 

 pinnated or bipinnated with one or two series of long, simple, distichous, 

 patent branches, articulated; the joints very variable in length in different 

 specimens, 5 10 times longer than broad, single-tubed, each bearing an 

 opposite pair of slender, pinnato-multifid or sub-dichotomous ramelli, 1 or 

 2 lines long, which in /3. are much drawn out, half an inch long, and 

 either simple or pinnate. Colour a fine transparent rose-red, perishing 

 quickly in the air or in fresh water. Tetraspores minute, elliptical, with 

 a wide border, sessile on the lower part of the ramelli, opposite or secund, 

 occasionally tufted. Favellce roundish, stalked and involucrated, contain- 

 ing clusters of pear-shaped spores. The ramelli are generally described as 

 dichotomous, but they are only so by abortion ; the true mode of branch-- 

 ing is pinnate, They are sometimes whorled, but more usually opposite. 



VTI. SEIROSPORA. Harv. [Plate 23, C.] 



Frond rosy, filamentous ; stem articulated, one-tubed, the 

 articulations traversed by jointed filaments; branches jointed. 

 Fructification: 1, Favellce (unknown); 2, oval tetraspores 

 disposed in terminal, moniliform strings. Name, 

 chain, and (TTropog, a seed. 



1. S. Grijfithsiana, Harv. Phyc. Brit. t. xxi. Callith. 

 seirospermmn, Griff, in Harv. Man. ed. 1, p. 113. Cal. 

 versicolor &. seirospermum. Harv. in Hook. Journ. Bot. vol. 

 \.p. 302; Wyatt.Alg. Danm. No. 19. 



On rocks and Algas, in 4 5 fathom water. Very rare. Torquay, Mrs. 

 Griffiths ; Salcombe, Mrs. Wyatf, Torpoint, Plymouth, Rev. W. S". Hore ; 

 Portaferry, Mr. Thompson ; ' Roundstone, W. H. H. ; Arran, Rev. D. 



