Plate LII. 



Fig. 236. CERAMIUM DESLONGCHAMPSII. 



Colour. Dark purple; almost blackish to the naked eye; on examination variegated 



with white. 

 Substance. Rigid' (for so delicate a plant). 



Character of Frond. Tufts of distinctly jointed threads {filameiits) . Filaments nearly 

 as thick as hog's bristles below; becoming gradually fmer upwards; much 

 branched in an irregularly forked manner; more or less furnished with very 

 slender, simple or forked branchlets. Tips fine; straightish; spreading. 



Joints. In variegated bands. Colourless and transparent in the middle; purplish and 

 opaque at and near the partition-lines (^dissepiments). 



Measurement. From 3 to 4 inches long. 



Fructification. Of two kinds, but only one clearly made out. Tetraspores set round 

 the joints; half-immersed; very prominent. The other, dark, irregular-shaped 

 lumps like clusters of small capsules, sessile on the stems and branches. 



Habitat. Our coasts generally. On rocks, &c. between tide-marks. Not uncommon. 



Fig. 237. CERAMIUM DIAPHANUM. 



Colour. Pinkish-red in general hue; but clearly variegated with white. 

 Substance. Kather soft. 



Character of Frond. Tufts of distinctly jointed threads {filaments). Filaments the 

 thickness of a hog's bristle below, becoming gradually finer upwards; irregu- 

 larly branched; partly forked, partly alternate; re-branched in the same way, 

 set at greater or less intervals throughout with short or long, more or less 

 forked branchlets, much more slender than the branches from which they 

 spring. Tips hooked inwards. 



Joints. In variegated bands. Colourless and transparent in the middle, red, opaque, 

 and swollen at, and near, the partition-lines {dissepiments), coloured bands wide 

 throuofhout. 



Measurement. From 2 to 6 inches long. 



Fructification. Of two kinds. 1. Minute spores in roundish capsules, with one or 

 two short branchletee;^« underneath ; sessile in the last forkings, or on the tips 

 of side branchlets. 2. Tetraspores set round the joints. 



Habitat. Our coasts generally. On the smaller algjB in tide-pools. Common. 



Fig. 238. CERAMIUM FLABELLIGERUM. 



Colour. Dull purple to the naked eye, on examination, of different shades. 

 Substance. Rigid. 



Character of Frond. Tufts of jointed threads {filaments) spreading fan-wise above. 

 Filaments as thick as hog's bristles; irregularly branched; partly forked; 

 partly alternate; much re-branched above; set with forked branchlets. Tips 

 pointed; straight and spreading; or somewhat curved inwards. 



Joints. In variegated bands, but wh^n young filled with a purplish fluid which 



hinders their detection. Afterwards colourless and transparent in the middle; ^ 

 purple and opaque near the partition-lines {dissepiments). These armed on one 

 side with a solitary, minute, coloured (when dry, white) thorn. 



Measurement. From 2 to 3 inches high. 



Fructification. Of two kinds. 1. Minute spores in large irregular-shaped capsules, 

 sessile on the branchlets, with two or three short branchletee>'^s underneath. 

 2. Tetraspores set round the joints. 

 Habitat. Our coasts generally. On the smaller algce, &c. between tide-marks. 

 29 



