Fig. 116. POLYSIPHONIA GRIFFITHSIANA. 



Colour. Brownish below; above, rosy pink. 



Substance. Rigid below; elastic; the branchlets soft; but not decomposing easily in 

 fresh-water. 



Character of Frond. Short tufts of jointed threads {filaments), very much branched. 

 Stems hogs' -bristle thickness at base, gradually finer upwards; alternately 

 branched throughout. Branches long, spreading; simple or divided; set with 

 numerous, variously branched, slender, spreading branchlets; the last ones often 

 bent back (re-curved). Length of joints equal throughout (wnich is not 

 usual). Marked by four upright lines (internal tubes) of irregular width. 



Internal Tithes. Four large, four small secondary ones. 



Measurement. Three or 4 inches long. 



Fructification. Only one kind observed. Clustered spores in broadly ovate capsules. 

 Habitat. Torquay. Parasitical on Folyides rotundus. Isle of Portland. Very rare. 



Fig. 117. POLYSIPHONIA ELONGELLA. 



Colour. Stems brownish; branchlets rose-red. Substance. Kigid below; soft above. 



Character of Frond. Small tufts of jointed threads {filaments), much branched. 

 Branching partly forked, partly alternate. Stems the thickness of a hog's- 

 bristle below, as fine as hau' above. Main branches distant; very wide-spread; 

 more or less furnished with soft tufts of long, often-divided branchlets, which 

 taper to the tips, but not, as in P. elongata, to the base also. Joints marked 

 v/ith two or three upright lines (internal tubes). 



Internal Tubes. Pour. 



Measurement. Prom 2 to 4 inches long. 



Fructification. Of two kinds. 1. Clustered spores in large, ovate, shortly-stalked 

 capsules; external. 2. Tetraspores, immersed in the middle of swollen 

 branchlets. 



Habitat. Our coasts generally; Isle of Man, West Coast of Scotland. On rocks and 

 stones and the smaller algae near low-water mark, and at a greater depth. 

 Pather rare. 



The winter and summer states of this plant differ as much as those of P. 

 elongata, which it strongly resembles in miniature; and which it is like in the 

 annual dying olf of its more delicate branchlets (see under P. elongata). But 

 there are certain marks by which the two may be distinguished. The branches 

 of P. elongella do not taper to the base like those of P. elongata; and the joints 

 are distinctly visible in all the main branches as well as in the branchlets. It 

 is also a much smaller and more delicate plant in general appearance. 



Fig. 118. POLYSIPHONIA CARMICHAELIANA. 



Colour. Peddish brown ; becoming black in drying. Substance. Pigid. 



Character of Frond. Tufts of jointed threads {filaments); branched. Stem set 

 throughout with scattered, alternate, wide-spreading branches of irregular 

 lengths. Branches short, scattered, alnriost horizontally spread, irregularly 

 forked {dichotomous), spine-like. Joints not visible in the stem and principal 

 branches, but these marked with from two to four upright lines (internal 

 tubes). Branchlets visibly jointed. 



Internal Tubes. Four. 



Measurement. Four inches long. 



Fructification. Has not been observed. 



Habitat. Appin. On Desmarestia aculeata. Veiy rare. 



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