THE MARINE BOTANIST, 75 



very irre^ilar in outline when old. In young- 

 specimens the surface is nearly flat and even ; but 

 in full-grown plants is exceedingly rough^, with 

 wart-like prominences. Structure very dense and 

 opaque. Fruit rare, and difficult to find. Colour 

 a dark-brown. Substance leathery, hard." — 

 Harv, Man.^ p. 49. 



ELACHISTA. 



Name the leasts from the small size of the plants. 

 Frond parasitical, consisting of a dense tuft of 

 free, simple, articulated, olive aceous filaments, rising 

 from a base composed of fibres, closely combined 

 together. Fructification ^ spores attached to the 

 bases of the filaments forming the tubercle. 



