160 THE MARINE BOTANIST. 



the midrib, usually near the ends of the branches. 

 Tetraspores either in proliferous leaflets, or in the 

 tips of the fronds. Colour, a dark red. Substance 

 in the stems and old plants firm, more tender 

 in summer than in winter. Grows on rocks 

 and the larger algae between tide-marks, and in 

 four to ten fathoms water. Biennial. 



DELESSERIA ANGUSTISSIM A. — NARROW 

 DELESSERIA. 



Frond compressed, very narrow, without any 

 membrane ; very nearly approaching to the above, 

 and not considered distinct from it by Dr. Harvey, 

 but admitted by him into his works in deference 

 to the opinion of Mrs. GriflGlths, who reckons it a 

 separate species. The extreme narrowness of frond 

 and entire suppression of the winged membrane 

 constitute the chief distinctions between this plant 

 and D. alata. Grows on the stems of Laminaria 

 digitata. Perennial. Winter and spring. Scar- 



