MYXONEMA 201 
ing, frequently elongated, beset with numerous, mostly opposite, 
divaricate branchlets ; branchlets thorn-like, tapering from a thick 
base to an acute point, often attenuate into rather short setae ; 
cells throughout cylindrical, about as long as broad, or a little 
longer or shorter, filled with the dense chromatophore ; diameter 
of the main branches about 14 4 (12-16), of the branchlets 
about 8 (م 6-9( م‎ at the base (p/. 30). 
In brooks and rills. 
New York: Bronx Park, June (607, 627); Botanical Garden, 
May (374, 422), June (629). 
New Jersey: Hudson Heights, April (309). 
Though our specimens average rather larger than the diameter 
given by Kützing (11-12.6 £), yet in general character they seem 
exactly to correspond with his description and figures. Taking 
into account the fact that Kützing’s description was based on dried 
specimens, the agreement is certainly as close as could be ex- ٭‎ 
pected. Rabenhorst seems quite to have misunderstood the 
nature of this species or of Stzgeoclonium protensum for the two 
are conspicuously incompatible ; the latter is an alternate-branched 
form, while this species is extreme in its development of the 
opposite type of branching. 
5. Myxonema ventricosum sp. nov. 
Cespitose, 5-10 mm. Jong; filaments much branched, branches 
mostly opposite, borne on small subglobose cells, often 2-4 pairs 
approximate, ascending ; branchlets alternate, opposite or subfas- 
ciculate, short, tapering slightly to arounded apex, sometimes pro- 
longed into a rather obtuse seta; cells below very strongly in- 
flated, 2-5 times as long as the central diameter, above shorter 
and less inflated, in upper branches cylindrical, about as long as 
the diameter or shorter; diameter of lower cells 14-16.5 ۸ at the 
dissepiments, 27-30 » in the center, 45-110 # long; diameter of 
branchlets at base 6-8 ۸ ( Pl. 37). 
On stones in the bed of a rapid brook. Cresskill, New Jersey, 
1 May 1900 (359). 
In the character of the upper branches this species resembles 
Myxonema lubricum and M. amoenum. The cells of the main 
branches, however, are very much more inflated than either of 
those forms. It is perhaps nearer to SZigeoclonzum insigne Nägeli 
(Pflanz-phys. Untersuch. 1: 36. ۸ 7. 1855), a beautiful species 
