164 CERAMIUM. 



distant, the upper closer, all the divisions erect and straight, 

 with narrow, acute angles ; the apices straight, or slightly 

 hooked inwards ; articulations colourless, those of the stem 

 and branches three to four times as long as broad, of the ra- 

 muli short ; dissepiments opake, purple ; favellae near the 

 tips of the branches, involucrate ; tetraspores erumpent, 

 bursting from the dissepiments of the larger branches. Gon- 

 groceras strict-urn, Kulz. Phyc. Gen. 



On mussel-shells &c. in tide-pools. Annual. Summer. Torquay, 

 Mrs. Griffiths ; Dingle, W. H. H. ; Roundstone, Mr. M'Calla. Fila- 

 ments as liue as human hair, densely tufted, not regularly dichotomous 

 nor forming fastigiate tufts, distantly branched below, more frequently di- 

 vided above. Articulations long in the middle of the filament. Colour 

 of the tufts, when strong, dark livid purple, paler and yellower in sunny 

 situations. Substance membranous, not very firmly adhering to paper. I 

 sent one of my Dingle specimens to Prof. Kutzing, who returned it with the 

 above name, It appears to be identical both with the Roundstone and 

 Torquay plants. The frond is more slender than in C. diapkanum, and 

 much more robust than in C. gracillimum. 



8. C. nodosum, Kiitz.; frond capillary, of equal diameter 

 throughout, rigid, dichotomous, excessively divided, fastigi- 

 ate ; the axils very patent ; articulations pellucid, those of 

 the middle of the stem from four to six times as long as 

 broad, the upper gradually shorter ; dissepiments swollen ; 

 tetraspores erumpent, two or three together on the outer edge 

 of short, accessory ramuli ; favellae at the apex of accessory 

 ramuli. Ham. Phyc. Brit. t. xc. 



On sandy shores, often at the roots of Zostera. Annual. Summer. 

 Generally distributed. Fronds '3 6 inches long, as fine as human bail- 

 or more slender, forming globular, fastigiate tufts, repeatedly dichoto- 

 mous with very patent axils, of nearly equal diameter throughout. Disse- 

 piments swollen, dark coloured ; articulations colourless. Substance rigid 

 and harsh to the touch when recent. In drying this plant imperfectly ad- 

 heres to paper. 



9. C. fastigiatum, Harv. ; filaments capillary, equal 

 throughout, dichotomous, level-topped; dissepiments opake; 

 lower articulations colourless, 3 or 4 times longer than broad, 

 upper coloured, short. Harv. in Hook. Journ. Sot. vol. i. p. 

 303 ; Wyatt, Alg. Danm. No. 87 ; Harv. Phyc. Brit. t. cclv. 



On rocks, &c., in tide-pools, rare. Torquay, &c. Mrs. Griffiths ; Ply- 

 mouth, Rev. W. S. Hore. Frith of Forth, Dr. Greville. Filaments 4 or 5 

 inches high, very slender, nearly of equal diameter throughout, regularly 

 dichotomous from the base ; the lower axils distant, the upper veiy close, 

 many limes forked ; the apices fastigiate and ho&"ked inwards. Lower arti- 

 culations generally 3 or 4 times as long as broad, colourless ; upper very 



