CHORDAKIACEvE. 71 



plants, and it will be useless for him to attempt to do so 

 without the aid of a microscope. 



Elachista fucicola. The Fucus-inhabiting 

 Elachista. 



Tufts brush-like; tubercle hemispherical; the outer 

 threads about au inch long, attenuated upwards, the in- 

 tervals between the joints once and a half to twice as long 

 as the threads are broad. Spores at first oblong, becoming 

 attenuated as they mature, attached to the terminal fibres 

 of the tubercle. 



This is the largest, best known, and most abundant 

 species of the genus. It grows on Fucus serratus and 

 F. vesiculosus. 



ZSIachista flaccida. Flaccid Elachista. 



Tufts brush-like ; tubercle small ; outer threads half an 

 inch long, tapering suddenly at the base, and gradually from 

 the middle to the tip, the intervals between the joints in the 

 lower half of the threads not quite half as long as the 

 threads are broad, increasing towards the tip until they are 

 as long or longer than the diameter of the threads. 



This species is usually found growing on Cystoseira 



fibrosa. 



Elachista stellulata. Starred Elachista 



Tufts very minute, star-like ; tubercle composed of large 

 cells ; outer threads very short, tapering at the base, the in- 

 tervals between the joints twice as long as the threads are 

 broad. Spores obovate, short-stalked, lodged among the 

 outer fibres of the tubercle. 



The only recorded specimens of this species are those 

 originally discovered by Mrs. GrifiBths, growing on 

 Bictyota dichotoma. The tufts are so extremely minute 



