Vegetative cells 60-68µ × 80-150µ, end walls plane; 3 chromatophores making .5-1 turn in the cell; fertile cells cylindrical; zygospores ellipsoid, 42-60µ × 80-120µ, median wall irregularly pitted, yellow-brown. Type in herb. E. N. T. Coll. No. 2666. Coffeen, Illinois.
This species is very distinct in the form of its spores and their position in the fertile cells. Lateral conjugation only has been observed. It is possible that the number of chromatophores is more variable, but in all the vegetative cells in which they could be counted there were three.
Spirogyra braziliensis (Nordstedt) nov. comb.
Owing to the indefinite and imperfect description of S. lineata Suring., the variety Braziliensis Nordstedt, of which we have a perfect description and specimens (W. & N. Alg. aq. dulc. exsicc. No. 360), should be given specific rank. Its connection with S. lineata is very problematical.
S. fluviatilis Hilse.
In all the published descriptions of this species the spores are described as smooth, and the number of chromatophores is given as four. I have seen many specimens from Illinois, and collections from the upper peninsula of Michigan (T. L. Hankinson), Minnesota (J. E. Tilden), Hawaii (J. E. Tilden), Massachusetts (P. B.-A. No. 1217), Pennsylvania (E. N. T.) and Guatemala (W. A. Kellerman). In all cases the mature spores are brown and scrobiculate, and the number of chromatophores is three or four.
S. nova-angliae nov. sp.
Cellulis vegetativis 50-60µ × 200-350µ, dissepimentis planis; chromatophoris 3-5, anfractibus arctis 2.5-4.5; cellulis fructiferis non inflatis; zygosporis ovoideis 50-65µ × 80-120µ: membrana media sporarum reticulata et dense punctata, flava.
Vegetative cells 50-60µ × 200-350µ, end walls plane; 3-5 chromatophores making 2.5-4.5 turns; fertile cells not inflated; zygospores ovoid 50-65µ × 80-120µ: median wall reticulate and densely punctate, yellow in color.
This species was first found in the collections of Mr. Bullard from Beaver Dam, Brook Pond, Natick; the pond west of Winter Pond, Winchester; and the Middlesex Fells, Mass. Recently the same form was found in a large prairie pond south of Coffeen, Illinois. Its position in the genus is near S. malmeana Hirn. In herb. E. N. T. Collections No. 2952, 2953 and 2900.