The Diatomaceæ of Philadelphia and Vicinity

by Charles S. Boyer

Conferva moniliformis Mueller (1783).

Conferva nummuloides Eng. Bot. pl., 2287, not Dillwyn.

Meloseira borreri Grev.

Lysigonium nummuloides (Lyngb., Kuetz.) O'Meara = Gaillonella nummuloides (Dillw.) Bory. See O'Meara, p. 248.

Marine and brackish. Long Island Sound and coast of New Jersey.

Pl. [1], Fig. 7.

LYSIGONIUM VARIANS (AG.) DE TONI

Frustules cylindrical, in long filaments, slightly constricted on each side of the suture; puncta in oblique rows in zone view. Valves 15-35 µ in diam. (De Toni), sub-plane, with fine puncta in lines radiating from the centre. Under medium magnification the frustules appear smooth. Very variable in size.

Meloseira varians Ag.

Fresh water. Common in ditches and springs.