MYXONEMA 197 
relation to his Draparnaldia tenuis, at one time making the latter 
a synonym under Conferva lubrica, and again making Conferva 
lubrica a variety of D. tenuis. After a very extended study of both 
these forms, there is no question in our opinion, of their distinct- 
ness, and we believe there is no doubt as to the correctness of the 
determination of the two as here described. Certainly there is no 
other American form that can be identified with Dillwyn's Con- 
Serva lubrica. 
Kützing’s figure of this species is only fair, and Berthold seems 
to be the only author who has particularly noted and correctly 
illustrated the small branch-bearing cells that are so characteristic 
of this and the rest of the forms of this group, though others 
have noted them in Stigcoclonium flagelliferum, and Kützing has 
given a hint of their presence in several forms. Miss Tilden (’96) 
has stated that, to her knowledge, such cells are a characteristic 
of no other species besides S. fagelliferum ; possibly this is an in- 
dication that the western algal flora is considerably different from 
that of the east, for here there are at least seven well-marked 
forms in which these cells are a prominent feature. 
Mvxonema lubricum may in some sense be considered a standard 
or point of departure for the comparison of the other forms of this 
group. Though it reaches a greater length than any of the other 
members of the group, they are for the most part more developed 
in some feature. The variety varians is smaller but rather more 
branched ; M. subuligerum has shorter cells, but more divergent 
and sharp-pointed branchlets; M. amoenum differs chiefly in the 
long cells of the main branches; M. flagelliferum might be con- 
sidered a form of the last with attenuated, setiferous branchlets ; 
M. ventricosum is a form in which the main cells are lengthened 
and inflated. These do not form an entirely progressive series, 
but are clearly related to M. lubricum. M. tenue is a much finer 
and somewhat simpler form, and might well be placed in the an- 
cestral line of M. lubricum. The probable developmental relation- 
ship would be better indicated if the alternate branched species 
were placed first and M. tenue made to form a connecting link 
with the larger forms of the /uóricum group. The present arrange- 
ment is simply more convenient for comparison. 
