. Fig. 269. CALLITHAMNION BYSSOIDEUM. 



Colour. A beautiful rose-red. 



Suhstance. Gelatinous; exceedingly soft and delicate; rather glossy when dry. 



Character of Frond. Dense tufts of excessively fine, jointed threads (^filaments) very 

 much branched. Stems very slender, much divided from the base, either into 

 several principal branches, bearing a great number of lesser ones; or wholly 

 composed of almost cobweb-like branches, inextricably entangled together. 

 Branches forming a lanceolate outline; clothed with long, slender alternate 

 branchlets, plumed like a feather, with a second lesser set, and these with 

 branchletee^s; all alternate. 



Joints. Distinct throughout. 



Measurement. From 1 to 3 inches long. 



Fructification. Of two kinds. I. Minute spores in large oval, twice-or-thrice-divided 

 capsules; near the ends of the branches. 2. Oval tetraspores ; mostly solitary; 

 sessile near the base of the branchlete6^^s. 



Hahitat. Our coasts in several places. Parasitic on other algse; on Codium 

 tomentosum especially. Near low-water mark. Not uncommon. 

 Like C. roseum, but much more cobwebby. 



Fig. 270. CALLITHAMNION POLYSPERMUM. 



Colour. Dull rose-red, or purplish. 

 Suhstance. Soft. 



Character of Frond. Dense round tufts of slender, jointed threads {filaments) ; loosely, 

 very much branched. Stems irregularly divided; somewhat naked below; 

 furnished with spreading branches above. Branches several times divided; set 

 with lesser branches; the larger ones bearing short, spine-like, alternate 

 branchlets; some quite simple, others re-branchleted, forming feather-like 

 plumes; the plumes long and narrow; the npper ones occasionally more 

 compound than those below. Branchlets spreading, occasionally even turned 

 back. 



Joints. Visible throughout. 



Measurement. From 1 to 3 inches in diameter. 



Fructification. Of two kinds. 1. Minute spores in large round capsules; sessile on 

 the branchlets. 2. Tetraspores set along the inner sides of the plumes of the 

 branchlets; very abundant. 



Habitat. Our coasts generally. On alg^e between tide-marks. Common. 



Fig. 27L CALLITHAMNION FASCICULATUM. 



Colour. A fine purple-red. 

 Suhstance. Soft. 



Character of Frond. Tufts of very slender, jointed threads {filainents) much and 

 bushily branched. Stems naked at the base, crowded above with long, wavy, 

 very upright branches; their upper half closely plumed like a feather with 

 branchlets. Lowermost branchlets (or plumes) short and simple; upper, long 

 and spreading; re-branchleted once and again near the tips; producing a blunt 

 outline. 



Joints. Obscnre in the nearly-opaque main stems. Visible in the branches. Partition- 

 lines {dissepiments) contracted. 

 Measurement. Two or 3 inches long. 



Fructification. Onlj'- one kind observed. Oval tetraspores at the base of the plumes 



of the branchlets. 

 Halitat. Yarmouth, Mr. Borrer. 



Surely only a " sport " of C. Borreri. 



42 



