Vegetative cells 30-36µ × 120-300µ, end walls plane; 1 chromatophore making 3-7 turns; fertile cells scattered in twos or fours among vegetative cells, or continuous, inflated on the conjugating side, outer side straight; conjugating tubes formed almost wholly by the male cell, zygospores ellipsoid 37-42µ × 57-70µ, median wall minutely punctate, yellow. Type in herb. E. N. T. Coll. No. 2470, 2953.
This species was first found in the West Big Four Pond, east of Charleston, Illinois. It has since been found in a collection from Chocorua, N. H., sent me by Mr. Chas. Bullard. It evidently belongs in the punctata group of the Spirogyras, but in form and markings of the spore, and the shape of the fertile cells it is amply distinct from its nearest allies; S. punctiformis Transeau and the next species to be described.
S. reflexa nov. sp.
Cellulis vegetativis 30-40µ × 120-300µ, dissepimentis planis; chromatophoris singulis anfractibus arctis 3-8 cellulis fructiferis binis vel quaternis inter cellulas vegetativas distributis, inflatis et valde reflexis; tubo conjugationis ex cellula mascula emisso; zygosporis ellipticis, 44-54µ × 90-150µ, membrana media glabra et luteo-brunnea.
Vegetative cells 30-40µ × 120-300µ, with plane end wall; 1 chromatophore making 3-8 turns; fertile cells in groups of 2 or 4, inflated or enlarged and strongly reflexed; conjugating tube formed by the male cells; zygospores ellipsoid, 44-54µ × 90-150µ, median wall smooth, yellow-brown. Type in herb. E. N. T. Collection No. 2661, 2664, 2912.
This species has been under observation for four years and has been collected from ponds near Casey, Lerna, Coffeen and Donnellson, Illinois. The large, smooth spores, the reflexed conjugating cells, and the tube produced wholly by the male cells are the distinguishing characteristics.
S. hydrodictya nov. sp.
Cellulis vegetativis 75-100µ × 210-360µ, dissepimentis planis, chromatophoris 7-10, modo subrectis longitudinalibus, modo spiralibus anfractibus arctis .1-.5; cellulis fructiferis inflatis vel subinflatis; tubo conjugationis ex cellula mascula emisso; zygosporis lenticularibus vel globoso-lenticularibus, 80-120µ × 110-195µ, membrana media scrobiculis obsita, brunnea.
Vegetative cells 75-100µ × 210-360µ, end walls plane, 7-10 chromatophores, either straight, or spiral making .1-.5 turns; fertile cells inflated or subinflated; conjugating tube formed by the male cell; zygospores lenticular or globose-lenticular 80-120µ × 110-195µ, median wall brown, pitted. Type in herb. E. N. T. Coll. No. 2661, 2665. Coffeen, Illinois.
This is one of the most remarkable forms described in this genus. It combines large size, the lenticular spore form, and the habit of forming the conjugating tube entirely by the male cell. The conjugating tube has walls heavier than those of any known species. Conjugation is both lateral and scalariform, and occurs between scattered cells, very rarely continuous for 6-8 cells. In the fruiting condition the filaments form a mesh-work which suggests the specific name. It has thus far been found only in the Fath Pond, north of Coffeen, Illinois.