BATRACHOSPERMUM. Ill 



branches. As it grows old the plant turns yellow and is 

 discoloured." 



The apices of the branches in young specimens are often 

 dilated, and all the filaments present in this state a greater 

 diameter, and a deeper colour, being usually glaucous green. 



Some specimens of what I regard as a variety of this 

 species were sent me by Dr. Dickie. They differed from the 

 species in its ordinary condition in the fact of the lower whorls 

 of the main stems being distinctly moniliform. 



8. BATRACHOSPERMUM ALPESTRE Shut. 

 Plate XIV. Fig. 2. 



Char. Frond black, very mucous, much branched ; alternately 

 forming very obtuse angles with the principal Jilaments. 

 Whorls of the stems spherical, distinct, but approximate, 

 branches compressed. 



Batrachospermum alpestre, Shuttleworth's MS. 



Hab. River Lea, Cheshunt : A. H. H. Ireland : W. H. 

 Harvey. 



It is now some three or four years since I first encountered 

 this species, from which time I regarded it as distinct from 

 any described British Batrachospermum, an opinion which 

 I was happy to have confirmed recently by the receipt of 

 a specimen marked B. alpestre Shuttleworth, and which 

 exactly accords with my own in all respects, except in being 

 much smaller. At the same time, Mr. Harvey, to whom 

 I was indebted for the authentic specimen of B. alpestre, 

 sent me a second example collected by himself, with the ob- 

 servation affixed to it, " very like B. alpestre, but I have 

 not examined it." 



This species is easily recognised by the eye alone, either 

 in its recent or dried state ; in the former its size, great 

 lubricity, jetty black colour, and approximate, yet for the most 

 part exactly spherical whorls, are remarkable ; in the latter, 

 in which also the black tint is preserved, it may be distinguished 

 by the multiplicity of its branches, which are, except the pri- 



