THE GREEN ALGAE OF NORTH AMERICA 317 



Var. POiA'CARPA (Nees and Mont.) Harlot, 1889-90, p. 15; 

 T. polycarpa, P. B.-A, No. 472 ; including T. Tucket manni 

 Mont. Membrane usually scabrous, gametangia larger, 24-45 p., 

 in long series ; both this and the following variety pass into the 

 type continually. Texas, Cal. So. Amciica. 



Var. SUBSIMPLEX (Caspary) De Toni, 1889, p. 237 ; P. B.-A., 

 No. 1377. Erect filaments simple or with one or two short 

 branches. Cal. Europe. 



Var. Pittieri (De Wildeman) nov. comb.; T. Pitticn De 

 Wildeman, 1894, p. 6. Filaments 18-25 ^ diam., smooth, cells 

 2-5 diam. long; gametangia globose or ovoid, 40 ^ diam., to 56 

 /u, long, borne at the extremity of branches 9-12 //, diam., cells 

 about 4 diam. long ; tips of branches, and especially of the 

 branches bearing gametangia, often coiling about other filaments 

 of the frond ; when this occurs with the fertile branches, there 

 ma} 7 be an appearance of a dense fascicle of gametangia on the 

 filament. On leaves of various plants. Costa Rica. 



The principal characters by which this could be distinguished 

 from T. aiirea are the rather larger and longer cells, the larger 

 gametangia, and the cirrhous branches ; but in view of the con- 

 siderable range of forms included under the species, these char- 

 acters do not seem sufficient to distinguish it. The gametangia 

 are so designated from their form and position, the original de- 

 scription designating them only as " zoosporanges." 



2. T. VILLOSA (Kiitz.) Hariot, 1889-90, p. 18 ; Wittr. and 

 Nordst., Alg. Exsicc., No. 1066. Erect filaments elongate, 

 tufted, flexuous, branching, pellucid ; cells 28-30 p. diam., 2-2^ 

 diam. long ; reproduction unknown. 



The type does not occur with us, but we have var. brachy- 

 meris Hariot, cells 28-32 /u, diam., 48-52 p. long. Dominica, 

 Guadeloupe, Mexico. Asia. 



The cells in the type are unusually long for this genus, but 

 shorter in the variety ; the diameter is quite uniform and larger 

 than all but quite exceptional forms of T. aurea. 



3. T. ABIETINA (Flotow) Hansgirg, 1886, p. 86 ; Wittr. and 

 Nordst., Alg. Exsicc., No. 917 ; Chroolepus abiciinum Kiitzing, 

 1854, PI. XCI, fig. 2. Forming reddish, more or less confluent 

 tufts, becoming ashy when dry ; cells of basal layer more or less 

 torulose, erect filaments cylindrical or in a few r of the lower cells 

 slightly torulose, 4-10 /u, diam., about 3 diam. long; terminal 

 cell sometimes considerably longer ; gametangia on special cells, 



