di-trichotomous branching, and by there bemg but a single 
articulation or ce// in the space intervening between each furca- 
tion; that is to say, every ézternode consists of a single cell. 
There is no other British species in which this takes place regu- 
larly, in all parts of the frond. It thus happens that the indi- 
vidual ced/s, in this species, are of extraordinary length, those of 
the lower parts of the filament bemg sometimes more than an 
inch in length, very frequently three quarters of an inch. 
Conferva pellucida was first described by Hudson, in the Flora 
Anglica, and has been adopted by all subsequent authors with 
the exception of Lyngbye, who unaccountably confounds it 
with C. rupestris, a plant which is well distmguished by the 
difference in its articulations, if there be no other character, as 
there are many, to separate it. Hudson’s expression “ articulis 
cylindricis longissimis,’ is alone characteristic of C. pellucida. 
Fig. 1. CLADOPHORA PELLUCIDA :—of the natural size. 2. Portion of a branch: 
—magnified. 3. Terminal articulation of the same :-—more highly magnified. 
