Himantidium maskellii, sp. nov.

Frustule: front view rectangular; length about four times the breadth, straight, forming a lengthened tenacious filament, showing lines of dots at the points of suture corresponding to the striæ on the side view. Valve: elongated, slightly arcuated, and attenuated towards the extremities, which are boldly rounded; both edges are sinuated; length about seven times the breadth. The convex edge has invariably one more bend than the concave. The valves vary in the number of the bends from 4/3 to 6/5. Striæ: parallel and transverse, and there are 23 to 27 to the .001 of an inch.

Hab.—Ngapari, Fernside, and River Avon, North Canterbury; Waikato and Cabbage Tree Swamp, Auckland (fossil)-Hutton; Cust Valley Swamp, North Canterbury (fossil).