Griffithsia.] ALG/E RHODOSPERME^. 211 



p. 336. Conf. diaphana, Dillw. t. 38. E. Bot. t. 1742. Cer. 

 rubrum, diaphanous var. Wyatt. Alg. Damn. No. 87. 



Sea-shore, on various Algae, common. 



3. C. fastigiatum, Harv. MSS. Fastigiate Ceramium. Fila- 

 ments capillary, equal throughout, dichotomous, level-topped ; 

 dissepiments opaque ; lower articulations hyaline, 3 4 times 

 longer than broad, upper coloured, short. Conf. fastigiata, 

 Roth. Cal. 2. p. 225. ? ? Cer. diaphanutn, ft. arachnoides, Ag. 

 Sp. v. ii. p. 152. Cer. diaphanum, Wyatt. Alg. Danm. 

 No. 86. 



Sea-shores. At the instance of my valued friend, Mrs. Griffiths, I 

 have ventured to separate this species from C. diaphanum, with which 

 all previous authors have confounded it. It has, however, a very dif- 

 ferent habit and ramification, and is, at least, as distinct as some other 

 species of the genus. Mrs. Griffiths has so well pointed out, in a letter 

 to me, the characters which peculiarly distinguish it from C. diapha- 

 num, that I cannot do better than quote her words : " Pray observe 

 that C. fastigiatum has no principal stem or branches ; that it is 

 uniformly and constantly dichotomous and level-topped, and that the 

 threads of which the tuft is composed are of an equal diameter from 

 the base to the summit ; and this holds good in plants from all parts of 

 the coast. Now C. diaphanum has a principal stem and branches, 

 divides irregularly, almost distichously, the extremities almost fan- 

 shaped, and very unequal at the top ; the joints are also more distant 

 and irregular." Mrs. G. in lift. 



4. C. ciliatum, Ducluz. Spiny Ceramium. Filaments ri- 

 gid, dichotomous, fragile ; articulations hyaline ; joints fur- 

 nished with whorled or solitary prickles ; apices remarkably 

 involute. Harv. in Hook. Br. Fl. v. ii. p. 336. Conf. ciliata, 

 Dillw. t. 53. E. Bot. t. 2428. 



On rocks, corallines, &c. A very variable plant, both in general ap- 

 pearance and in the nature and number of the prickles ; and, perhaps, 

 future observations may show the propriety of resolving it into several 

 species. But without a careful examination of specimens from all parts 

 of the coast, such a proceeding would, in all probability, serve no other 

 purpose than that of burdening the science with useless synonyms. 



54. GRIFFITHSIA. Ag. Griffithsia. 



Frond filamentous; filaments articulated throughout, mostly 

 dichotomous ; ram uli single -tubed, often whorled; dissepi- 

 ments hyaline. Fructification double : 1. clustered capsules 

 with hyaline pericarps ; 2. roundish, gelatinous, involucrated 

 receptacles (flavellcej, including minute granules. Named 

 by Agardh, in honour of Mrs. Griffiths of Torquay, a most 

 acute and indefatigable Algologist, to whose exertions the 

 British Flora stands indebted for many of its most beautiful 

 species. 



1. G. equisetifolia, Ag. Equisetum-like Griffithsia. Fila- 



