Plate XV. 



Fig. 59. LEATHESIA BERKELEYI. 



Colour. Dark brown. 

 Substance. Flesh}^; soft; solid. 



Character of Frond. Convex lumps, somewhat depressed; more or less globose; 

 growing in patches upon rocks. 



Measurement. From 1 to 2 incbes in diameter. From 1 to J an inch tbick. 



Fructification. Minute seeds (sijores) concealed in tbe substance of the frond. 



Habitat. South of England. West of Ireland. On rocks between tide-marks. 



For another Leatliesia, see Plate XIII. Fig. 54. 



Fig. 60. EALFSIA VERRUCOSA. 



Colour. Dark brown. 

 Substance. Leathery; hard. 



Character of Frond. Crustaceoiis ; i. e. an incrustation, forming lichen-like patches 

 on rocks. When young, circular in outline; becoming very irregular when 

 old. The surface of young specimens flat. That of full-grown ones rough 

 with wart-like prominences. 



Measurement. Patches from 1 to 6 inches in diameter. 



Fructification. Minute seeds (scores) in the wart-like prominences, scattered over 

 the surface of the frond. 



Habitat. Our coasts generally. On rocks between tide-marks. Common. 



Fig. 61. ELACHISTA FUCICOLA. 



Colour. Olive; or rusty brown. 

 Substance. Soft; membranaceous. 



Character of Frond. A small, very dense tuft (rising from a tubercle), parasitic on 

 Fucus vesiculosus. Threads (f laments) of the tuft, simple; tapering to the 

 tips; jointed. 



Measurement. About an inch long when full-grown. 



Fructification. Minute seeds {spores) concealed in the substance of the tubercle. 

 Habitat. Our coasts generally. On Fucus vesiculosus. Very common. 

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