CERAMIUM. 163 



diameter 01 me ^u.u from which they spring; the ^o o^n-auing, not 

 hooked in. The whole frond variegated "with dark purple ; the joints trans- 

 parent. To the naked eye the tuft has a blackish look : the substance is 

 rigid, cartilaginous, and it adheres pretty fully to paper. Favellce very irre- 

 gular in form and size, having a distorted appearance, usually lobed, 

 bursting from the stems over which they are thickly scattered, destitute of 

 involucral ramuli ; tetraspores large and very prominent, seated in the 

 joints, of ten of the same plant which bears "favellce." 



5. C, diaphamim, Ag. ; frond setaceous, attenuated up- 

 wards, rather flaccid, irregularly dichotomous, the lower 

 forkings distant, the upper close together ; branches set with 

 short, lateral, dichotomous ramuli ; articulations colourless, 

 those of the main stems 3 or 4 times as long as broad, of the 

 ramuli short ; dissepiments swollen, opake ; apices hooked 

 inwards ; favellae near the tips of the branches, subtended 

 by ramuli; tetraspores whorled in the joints, depressed. 

 Hook. Br. Fl. ii. p. 336 ; Wyait y Alg. Damn. No. 87 ; Harv. 

 Phyc. Brit. t. cxciii. Conf. diaphana, E. Bot. t. 1742. 



On the smaller Algae in tide-pools. Winter and summer. Stems tufted, 

 2 6 inches high, the thickness of hogs' bristles, irregularly or sub-dicho- 

 tomously branched, the branches set at greater or less intervals with short 

 or long dichotomous ramuli, two lines to half an inch long, which are 

 constantly greatly more slender than the branches from which they spring, 

 generally not more than a quarter their diameter ; the tips generally hooked 

 inwards. The whole frond is distinctly jointed, the dissepiments darkly 

 coloured, the intervals pellucid, giving the filament a beautifully varie- 

 gated appearance. Favellce near the tips of the branches, roundish or 

 somewhat lobed, generally subtended with one or two short ramuli ; tetra- 

 spores prominent, large, with a pellucid case, seated in the coloured portion 

 of the joints. 



6. C- gracillimum, Kiilz. ; frond excessively slender, of 

 nearly equal diameter throughout, very flaccid and gelatin- 

 ous, dichotomous ; the branches set with minute, flabelliform, 

 dichotomous ramuli; articulations colourless, those of the 

 branches five or six times as long as broad, those of the ra- 

 muli very short ; dissepiments opake, purple ; favellae borne 

 on the lateral ramuli, with a spreading, many-rayed involucre. 

 Harv. Phyc. Brit. t. ccvi. 



On mussel-shells, and on Corallina officinalis and other small Algae, be- 

 tween tide-marks. Annual. Summer and autumn. West of Ireland, 

 and South of England, in several places. Filaments 2 3 inches long, 

 much more slender than a human hair, flaccid and tender, irregularly di- 

 vided, set with minute, many-forked ramuli of fan-like outline. Colour 

 a dark, reddish purple. 



7. C. strict um, Kiitz. ; frond capillary, nearly equal, 

 membranaceous, irregularly dichotomous, the lower forkings 



M 2 



