Plate LXIII. 
Fig. 294. CLADOPHOEA PELLUCIDA. 
Colour. A fine, glossy, transparent green ; fading in the herbarium. 
Sulstance. Eigid ; wiry ; adhering very imperfectly to paper. 
Character of Frond. Thread-like (^filamentous) ; jointed ; solitary or slightly tufted ; distantly, 
much branched. Stems as thick as a hog’s bristle ; undivided at first ; then forked 
(^dichotomous), or three- (or even four-) armed (trichotomous) ; and, more or less, regu- 
larly continuing this character throughout. Upper branches furnished with branch- 
lets of the same three-armed growth ; or occasionally tufted. Branches re-branchleted. 
Joints. From three-quarters of an inch to an inch long below ; shorter upwards ; branches 
springing from all the partition -lines {dissepiments) ; filled with green colouring 
matter {endochrome). 
Measurement. From 4 to 6 inches long. 
Fructification. Minute seeds (zoospores^; so called from having at one period a motion as if 
endowed with animal life) ; formed of the colouring matter in the joints ; and in 
due time bursting through them. 
Habitat. Our coasts generally. In deep rock-pools near low-water mark. Not very common. 
* This explanation of the word zoospores need not, surely, be continued longer. 
C. pellucida is, from its extremely long joints and three-armed branching, a quite clearly 
marked British species. 
Fig. 295. CLADOPHOEA EECTANGULAEIS. 
Colour. A full green ; fading in the herbarium. 
Substance. Eigid ; bristling ; adhering very imperfectly to paper. 
Character of Frond. Thread-like {filamentous) ; jointed ; several growing near together and 
entangled in intricate bundles ; distantly, much branched. Filaments as thick as 
hogs’ bristles throughout ; set with long, wavy, wide-spread, exactly opposite 
branches ; or, occasionally, irregularly divided. Branches rebranched in the same 
way ; more or less furnished with very short, exactly opposite, horizontal branches, 
which are sometimes simple ; sometimes re-branchleted with a second similar set. 
Joints. Twice or thrice as long as broad throughout ; filled with green colouring matter 
{endochrome). 
Measurement. From 8 to 12 inches long. 
Fructification. Minute seeds {zoospores) formed of the colouring matter in the joints ; and 
in due time bursting through them. 
Habitat. Abundant in Eoundstone Bay. Arran. Torquay. Thrown ashore. Very rare 
generally. 
Another most clearly marked species ; but, unluckily, extremely rare. The tiny, exactly 
opposite hranchlets, are found on no other British Cladophora. 
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