112 BATRACHOSPERME.E. 



mary ones, exceedingly short and irregular, and issue from 

 the main filaments almost at right angles, and by their non- 

 moniliform appearance. In drying, also, it shrinks consider- 

 ably. It is a well marked, but apparently not an uncommon 

 species. I am not able to refer it to any described by Bory. 

 My specimens were met with during the summer in a rapid 

 part of the river Lea, near Waltham Abbey, attached 

 to piles of wood, which they almost covered. The length 

 of some of them reached to four inches ; their great size, 

 the elegance of their movements, and their dark colour, 

 at once struck me, and made me desirous of securing speci- 

 mens, which it was not easy to do in consequence of the 

 depth at which they grew. I succeeded, however, in obtain- 

 ing a few at the imminent risk of immersion. 



9. BATRACHOSPERMUM PROLIFERUM Hass. 

 Plate LXIII. Fig. 1. 



Char. Frond grey, branches irregular, divaricate, beset 

 with short ramuli, which are pinnate. Whorls of the 

 stems approximate, compressed, almost confused, in the 

 pinnate branches, subdistant, distinct, formed of very J ew 

 Jilaments. 



Batrachospermum moniliforme, B. proliferum, Carmichael. 



Hob. Appin : Captain Carmichael. 



I have seen but one specimen of this curious and in- 

 teresting species, for an examination of which I was in- 

 debted to Mr. Harvey : not the slightest doubt, however, 

 remains on my mind of its distinctness ; it is certainly no 

 less distinct than rare. Captain Carmichael, to whom algolo- 

 gists are deeply indebted, for numerous additions to both 

 the marine and freshwater divisions of the Alga, and whose 

 powers of observation were of a very high order, thus in his 

 MS. describes the plant in question. " Frond, solitary or 

 in small clusters, one or two inches long, irregularly branched ; 

 branches divaricate, curved or flexuous, opaque and very 

 dark coloured, beset with short ramuli, which issue out from 



