THE GREEN ALGAE OF NORTH AMERICA 317 



Var. POLYCARPA (Nees and Mont.) Harlot, 1889-90, p. 15; 

 T. polycarpa, P. B.-A, No. 472 ; including 7\ Tucket manni 

 Mont. Membrane usually scabrous, gametangia larger, 24-45 /x, 

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

 type continually. Texas, Cal. So. Atneiica. 



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

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

 branches. Cal. Europe. 



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

 Wildeman, 1894, P- 6. Filaments 18-25 /* diam., smooth, cells 

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

 P. long, borne at the extremity of branches 9-12 p. 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 

 may 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. an re a 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 p. 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 abietinum 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 of the lower cells 

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

 cell sometimes considerably longer ; gametangia on special cells, 



