336 ALGiE CONFERVOIDEiE. [Spyridicl. 



set in a double or triple series. Very distinct from the last in 

 habit and character. A careful examination of original specimens 

 enables me to refer Dillwyn's tab. G. (C. Arbuscula) which has created so 

 much perplexity, to the present species, as well as so much of his de- 

 scription {Spi. Conf. p. 80) as relates to the fruit. His t. 85, however, 

 with the accompanying description, belongs to Calidhamnion Arbuscula. 



61. Ceramium. Adans. Roth. Ceramium. 



Filaments articulated, mostly dichotomous, reticulated with 

 veins : dissepiments opaque. Fruit double ; — 1. capsules with a 

 membranaceous pericarp, containing numerous angular seeds. 2. 

 simple oblong granules imbedded in the upper ramuli. — Name, 

 xzpxfiog, a little pitcher, in allusion to the form of the capsules; 

 but, as the genus now stands, the resemblance is not striking. — 

 This is the Boryna of French authors. 



1. C. rubrum, Ag. (red Ceramium); filaments cartilaginous 

 reticulated, articulations opaque, dissepiments contracted. — 

 Ag. Sp. Alg. v. 2. p. 146. — Conferva rubra, Dilho. Conf. t. 34. 

 E. Bot. t. 1166. — /S. Ceram. secundatum, Lyngb. Hydroph. 

 Dan. t. 37. 



On rocks and Algae, abundantly. — Very variable in ramification and 

 colour ; but easily distinguishable by the above characters. 



2. C. didphanum, Roth, (variegated Ceramium); filaments 

 flaccid, articulations hyaline, joints swollen opaque. — Ag. Sp. 

 Alg. v. 2. p. 150. Conferva diaphana, Dillw. Conf t. 38. E. 

 Bot. t. 1742. 



Sea-shore, on various Algse, "never on rocks," Greville, common.— 

 Less variable than the last, and conspicuous among the Alga? for its 

 beautifully variegated filaments. 



3. C. cilidtum, Ducluz, {spiny Ceramium); filaments rigid 

 fragile, joints furnished with whorled or solitary prickles. — 

 Ag. Sp. Alg. v. 2. p. 153. Conferva ciliata, Dillw. Conf t. 53. 

 E. Bot. t. 2428 ]8. acanthonotmn, (Carm 31SS.) ciliae uni- 

 lateral, solitary on the outer side of the articulations. 



On rocks, corallines, &c, common. — ft Appin, Capt. Carmichael. 

 Dunmore, near Waterford, Miss Anne Taylor. — A variable plant, but 

 distinguished from either of the former by its rigid and fragile filaments, 

 which, as Mr. Sconce well observes, " break in the hand, as if the joints 

 separated like those of an Equisetum." 



62. Spyridia. Harv. Spyridia. 



Main filaments inarticulate, cartilaginous, beset with articulat- 

 ed ramuli; dissepiments opaque. Fructification; — 1. trisporous 

 capsules with hyaline pericarps clustered round the bases of the 

 ramuli: 2. pedunculated gelatinous receptacles with membran- 

 aceous pericarps, often surrounded by an involucre of short ram- 

 uli, containing two or three masses of roundish granules. — 



