250 THE MARINE BOTANIST. 



CERAMIUM STRICTUM. — CLOSE-FORKED 

 TRANSPARENT-JOINTED CERAMIUM. 



" Frond capillary, nearly equal, membranaceous, 

 irregularly dichotomous, the lower forkings distant, 

 the upper, closer; all the divisions erect and 

 straight, with narrow, acute angles; the apices 

 straight, or slightly hooked inwards ; articulations 

 colourless, those of the stem and branches three to 

 four times as long as broad, of the ramuh short ; 

 dissepiments opaque, purple; favellae near the tips 

 of the branches involucrate ; tetraspores, bursting 

 from the dissepiments of the larger branches. The 

 frond is more slender than in C, diaphanumy and 

 much more robust than in C. gracillimumr This 

 species grows in dense tufts, the filaments all 

 spreading out very straightly, and dividing into 

 pencilled tufts near the tips ; the colour of the tuft 

 is either a dark livid purple, or yellowish purple 

 when growing exposed to the sunshine. Attached 

 to mussell-shells, &c., in tide-pools. Annual. Sum- 



