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 fi (12-16 fi), of the branchlets 

 about 8 (J. (6-9 ju) at the base (//. jo). 



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 Kiitzing (1 1— 12.6/*), yet in general character they seem 

 exactly to correspond with his description and figures. Taking 

 into account the fact that Kutzing'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 Stigeoclonium 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. no v. 



Cespitose, 5-10 mm. long; 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 a rounded 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 (i at the 

 dissepiments, 27—30/7. in the center, 45— 1 10/7. long; diameter of 

 branchlets at base 6-8 fi {pi. ji). 



On stones in the bed of a rapid brook. Cresskill, New Jersey, 

 I 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 Stigeoclonium insigne Nageli 

 (Pflanz-phys. Untersuch. 1: 36. pi. 1. 1855), a beautiful species 



