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. =S. diluta= Wood. I first came across this species in Mr. Bullard’s collection from the pond west of Winter Pond, Winchester, Mass. On going over Wood’s description, its identity with _S. diluta_ is unmistakable. The position, color and form of the spore, and the shape of the fertile cells is perfectly represented in Wood’s figure. The dimensions also correspond. Wolle is responsible for confusing this species with _S. nitida_ (Dillw.) Link, but a glance at Wood’s figure is sufficient to show that it is very different from that species. The P. B. A. specimen No. 513 (labelled _S. nitida_) from Bridgeport, Conn., belongs here. Miss Grace Stone also sent me a collection of this species from near New York City. In the U. S. National Herbarium is another specimen from Bois Sabbi, Louisiana, April 7th, 1891, (A. B. Langlois). Recently the species has been collected at Donnelson, Illinois, by Mr. Frank Harris.