PALMELLACEiE. 
119 
Fronds attached at base, one or two feet long, from one to four lines in diameter, 
very much and irregularly branched ; branches scattered or crowded, simple or divided, 
a foot or more in length, attenuated to a fine point, sometimes smooth and naked, but 
generally densely clothed with slender, villous ramenta, spreading to all sides. The 
gelatinous tubes or sheaths in which the cells are seriated are very obvious, and lie close 
together in longitudinal, parallel strata. The cells are of large size, bright-green colour, 
and variable shape ; some are twice as long as others. 
This I had at first supposed to be a new species, but now regard it as a very gigantic 
state of H. penicillatus , A g. which under various forms and of various sizes is common 
in alpine streams in Europe. I fear characters derived from the shape and size of the 
cellules are not more to be depended upon than are those taken from the ramification. 
