Supplement to his work on Confervee. It does not appear to have 
been noticed by earlier writers. It is very closely related to C. arcta 
and C. wacialis, from the former of which it differs chiefly by its 
smaller size and less branching filaments, and from the latter 
more by habit than by any very decided characters. The so- 
called species of the genus Cladophora ought, in many cases, to be 
regarded more properly as tolerably constant forms or varieties, 
than truly distinct organisms ; but as similar doubts of the vali- 
dity of species encumber the nomenclature of plants far higher m 
the system, we may the more readily tolerate them here. 
The proper time has, perhaps, arrived for dismembering the old 
genus Conferva, Ag., as proposed by several continental authors 
and carried out in this country by Mr. Hassall in his “ Fresh-water 
Algee.” Kiitzing, whose name Cladophora I here adopt (although 
in strict justice Chloroniton, Gaill., ought to be preserved), dis- 
tributes the Agardhian Confervee into twelve genera, six of which 
only concern the British Flora. Of these Gdogonium, Link, is - 
identical with Mr. Hassall’s Vestculifera, and with the still older 
Tiresias, Bory, which latter name should be adopted. Conferva 
is retamed for the species with simple threads, whose fruit is im- 
perfectly known. 2/zzogonium is proposed for Conf. riparia, Ag.,— 
and its allies; while Agagropila, founded on C. egagropila and 
Spongomorpha, on C. uncialis, 1 clude m the genus now called 
Cladophora. \t would be clearly a most artificial arrangement 
to separate C. wncialis generically from C. /anosa and C. arcta. 
Fig. 1. CLADOPHORA LANOSA :—natural size. 2. Portion of a filament 3. Por- 
tion of the lower part of a filament. 4. Apex of ditto :—magnified. 
