Plate LX. 



Fig. 278. CALLITHAMNION ROTHII. 



Colour. Deep red or purple. 

 Substance. Soft and velvety. 



Character of Frond. Dense tufts of very short, fine, jointed threads {filaments) ; 

 forming velvety patches on rocks. Filaments very slender; of one thickness 

 throughout, slightly forked, irregularly branched. Branches very upright, rod- 

 like; the upper ones sometimes set with a few secund simple or branched 

 branchlets, on some of which the tetraspores are borne. Tips pointed. 



Joints. Visible throughout. 



Measurement. From ^ to 1 inch high. 



Fructification. Only one kind known. Small round tetraspores, often clustered 

 together, borne on the (then) shortened end branchlets. 



Sahitat. Oar coasts generally. Spreading over the surface of rocks at half-tide 

 level. Common. 



Fig. 279. CALLITHAMNION MESOCARPUM. 



Colour. Purplish-red. 

 Substance. Soft, velvety. 



Character of Frond. Tufts of minute, jointed threads {filameiits), forming a broad, 

 shaggy, purple crust on the rock. Filaments rising from creeping fibres, up- 

 right, simple or sparingly branched. Branches alternate, very upright; naked, 

 or bearing a few little upright, often secund branchlets, on some of which 

 the tetraspores are borne. 



Joints. Visible throughout. 



Measurement. One-fourth or ^ of an inch high. 



Fructification. Only one kind known. Oval tetraspores borne on the (then) short- 

 ened branchlets; often two on a branchlet. 



Sabitat. Appin. On rocks at low-water mark. 



Fig. 280. CALLITHAMNION SPARSUM. 



Colour. Purplish-red. 

 Substance. Soft, velvety. 



Character of Frond. Very minute, scattered tufts of fine, jointed threads (^filaments'). 

 Filaments nearly simple, upright, slightly branched upwards. Branches spread- 

 ing; of unequal lengths, alternate or secund; the tips blunt. 



Joints. Visible throughout. 



Measurement. Scarcely of an inch high. 



Fructification. Only one kind known. Bluntly oval tetraspores; sessile generally in 

 the angles of branching (axils). 



Habitat. Appin. Miltown Malbay. On old stems of Laminaria saccharina, and on 

 Cladophora rupestris. 



Very little observed, owing to its minuteness ; but not uncommon. 



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