Art. LIV.—On a new Variety of Desmid.
[Read before the Wellington Philosophical Society, 24th February, 1886.]
Genus Triploceras, Bailey.
Triploceras tridentatum, Maskell; var. superbum, var. nov.
Frond slender, elongated, cylindrical, very slightly depressed at the middle.
Denticulate lateral projections of the segments large, somewhat prominent, tri-dentate, the middle tooth the largest. Edges of frond between the projections slightly curved inwards, so that the segments appear as if with several toothed transverse rings. Denticulations pointing at right angles to segment near the constriction, and slightly forward near the extremities. The small processes at the base of the terminal tridentate prolongations sharply pointed forwards, not tri-apiculate. Terminal processes, 2, sub-rectangular, tri-dentate.
Endochrome, not very dark-green.
Length of frond, about 625 μ; breadth near constriction, about 50 μ.
From Wainui-o-mata, near Wellington.
This is a more ornate and elegant plant than T. tridentatum, or its other variety, cylindricum, on account of the more complex lateral denticulations. In the locality mentioned it seems to be somewhat abundant: it is quite constant in its characters.