CONFERVACEjE. 273 



posed are marine, and others fluviatile. They are all 

 comparatively insignificant, and their characters are dif- 

 ficult to determine, and still more difficult to describe in 

 intelligible language. 



Chsetomorpha Melagonium. The dark-green 

 Chsetomorpha. 



Root shield-shaped. Threads robust, bristle-like, erect, 

 rigid, growing singly or several together ; cells about twice 

 the length of their diameter. 



This species grows on rocks in tide-pools near low- 

 water mark, and is perennial. It is widely distributed, 

 and may be readily distinguished by the thickness and 

 wiry texture of its filaments. It was formerly Conferva 

 Melagonium. 



Chsetomorpha serea. The pale-green Chseto- 

 morpha. 



Root shield-shaped. Threads bristle-like, straight, rigid, 

 brittle, growing in tufts; cells about the length of their 

 diameter. 



This species grows on sand-covered rocks between the 

 tide-marks, and is common on the British coast. It is 

 less rigid, more slender, and of a much paler colour 

 than C. Melagonium. It was formerly a Conferva. 



Chsetomorpha sutoria. The bristle Chseto- 

 morpha. 



Threads from a few inches to a foot or more long, bristle- 

 like, curved, growing, unattached and floating, in large, 



T 



