Plate LVI. 



Fig. 256. CALLITHAMNION BARBATUM. 



Colour. A brownish or full red. 



Substance. Membranaceous, and sonaewhat rigid. 



Character of Frond. Dense tufts of jointed threads {filaments); irrenjularly branched. 

 Stems rising- from creeping fibres bearing opposite, or sometimes alternate, 

 branches. These long, and either simple or clothed for half their length (and 

 irregularly here and there) with minute, opposite, spine-like branchleted;i6-, which 

 die down in winter. 



Joints. Visible throughout*; deeply coloured. 



Measurement. From 1 to 2 inches long. 



Fructification. Only one kind known. Narrow oval tetraspores, sessile on the lower- 

 most joints of the branchletmzs. 



Hahitat. Ilfracombe, Penzance, and Weymouth. On mud-covered rocks within tide- 

 marks. Very rare. 



* " When examined under the microscope," must always be understood in speak- 

 ing of these delicate plants. 



Fig. 257. CALLITHAMNION BRODIiEI. 



Colour. A brownish red. 



Substance. Soft generally ; stem elastic. 



Character of Frond. Thread-like {filamentous); jointed; tufted or single; much 

 branched. Stems hogs'-bristly below, becoming finer above; generally simple; 

 furnished throughout with long, alternate, wide-spread branches, the lower- 

 most longest. These bearing a secondary set, one to each joint, which spring 

 in succession from each side of the stem (quadrifariousli/) ; the lowermost always 

 longest; so that each branch has a spear-shaped outline. Secondary branches 

 once or twice re-branched in the same way. Last branclilets somewhat back- 

 curved; bearing towards their tips a few secund branchletee/^s. 



Joints. Obscure in the stems, which are somewhat opaque and veiny; visible in the 

 branches and branchlets. 



Measurement. From 1 to 3 inches long. 



Fructification. Of two kinds. 1. Minute spores in large, roundish, solitary, or 

 double capsules; sessile on the branchlets. 2. Globose tetraspores^ sessile on 

 the branchletde/i5. 



Habitat. Our coasts generally. On algte near low- water mark. Rare. 



Fig. 258. CALLITHAMNION BRACHIATUM. 



Colour. Brownish red; becoming darker in drying. 

 Substance. Rigid for so delicate a plant. 



Character of Frond. Thread-shaped {filiform); jointed; tufted or single; much 

 branched. Stem the thickness of a hog's bristle; simple, or nearly so; set with 

 branches which spring in succession from all sides {quadrifariously). Branches 

 often re-branched in the same way; last set but one, slender, drawn out; fur- 

 nished with short, alternate tufts of branchlets. Branchlets upright, awl- 

 shaped; not tapering to the base, but gradually upwards to a fine point. 



Joints. Obscure in the main stems, which are somewhat opaque and veiny; visible in 

 the last branches and branchlets. 



Measurement. From 1 to 1^ inches long. 



Fructification. Only one kind known. Minute oval tetraspores^ sessile near the tips 



of the branchlets. 

 Habitat. Our coasts generally. Parasitic on the larger .algie. 



Probably only a slender variety of C. tetragouaiii. 



2.1 



