1879.] eS (Halsted. 
B. Ultimate divisions of leaves two celled. 
1. Whorls loosely branched. N. gracilis (Sm.) Ag. 
2. Whorls compact. N. tenuissima Kitz. 
C. Ultimate divisions of leaves three celled. 
1. Whorls very large and spreading. N. intricata Roth. 
Nitella opaca Ag. 
Nitella opaca Ag. Agardh, Syst. Alg., 24; Wallman, Char., 31; 
A. Braun, in Krypt. Fl. Schlesien, 397. Nitella syncarpa var. 
glomerata A. Braun, Schweiz. Char., 7; Kiitz., Sp. Alg., 614. Ni- 
tella syncarpa var. Smithi Coss. and Germ., Fl. Env. Par., 662. 
Chara syncarpa var. opaca A. Braun, in Flora, 1835, 1, 52; Kiitz., 
Phyc. Germ., 256. 3 
Exzsiccatae: Braun, Rabenhorst and Stizenberger, Char. Exsic., 29, 
51, 52 and 53. 
~ Illustration: Coss. and Germ., Atlas, Tab. 39. 
Plants diwcious, medium size, transparent; whorls small, remote, 
approximating at the extremities of the stem, primary ones usually 
sterile; leaves twice or thrice branched, ultimate divisions single- 
celled, apex obtuse. Antheridia .50—.65 mm. in diameter, numerous, 
single, on small leaves; without gelatinous covering. Sporangia 
ovoid .7-1.0 mm. long; 5-6-striate, on short leaves which form loose. 
heads: crown often deciduous. 
This species, so abundantly represented in the Braun, Raben. and 
Stiz. Exsic. is with us comparatively rare. It has been found only in 
the far west: North-western Nevada, (Bailey). 
In size, flexibility and color it much resembles Chara coronata var. 
Schweinitzii; but is readily distinguished from it, as well as from 
most of the American members of its own genus, by its dicecious 
character. 
Nitella capitata Ag. | 
Nitella capitata Agardh, Syst. Alg., 125; Wallman, Char., 37; 
A. Braun in Krypt. Fl. Schles., 396. Nitella syncarpa var. 
oxygyra A. Braun, Schweiz. Char., 7. Nitella syncarpa var. ca- 
pitata and gleocarpa Kiitz., Phycol. germ., 256; Sp. Alg., 514. 
Exsiccatae: Braun, Raben. and Stiz., Char. Exsic., 26, 27 and 28. 
Illustration: Meyen in Linnaea, 11, Tab. 3. 
Plants dioecious, large, much branched, dark brown when dried; 
whorls remote, consisting of few and long undivided leaves. Sexual 
organs with gelatinous covering. Antheridia numerous, at apex of short 
eaves, forming clusters. Sporangia small, 6-8-striate, nearly spher- 
