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and the transverse 0.07 mm. The central chamber is 0.025 mm. in width and there are four or five chambered rings, which are thicker than in the previous form. In diabase tuff at the River Badoengan.

Porodisctis elegans sp. nov. PI. I, fig. 24.

The test is a short oval, 0.075 mm- in length and 0.06 in width. The central chamber is 0.02 mm. in width, and there are from four to five chambered rings, each about 0.006 mm. in width, surrounding it. This is a shorter form than either ot the preceding. In diabase tuff from the River Badoengan.

Porodisctis tenuis, sp. nov. PI. I, fig. 25.

In section the test is oval in outline; the long diameter o. 1 1 mm. and the transverse 0.09 mm. The small central chamber is only 0.006 mm. in width; it is surrounded by 3—4 chambered rings, each about 0.015 mm- width. The outer ring is apparently a spiral, the inner rings are concentric. It resembles P. cretaceus, Rüst (Pal. Bd. xxxiv, p. 198, pl. xxiv, fig. 8) as regards size, but in this species, the chambers are all spirally arranged. In red jasper near Loeboek Antoe, Sarawak; rare.

Genus Stylodictya Haeckel.

The test is a flat disc with a simple central chamber surrounded by concentric rings, divided by radial beams; the margin of the test with some irregularly distributed radial spines.

Stylodictya fimbriata, sp. nov. Pl. IV, fig. 38.

The test is oval in outline, the long diameter 0.17 mm., the transverse o. 15 mm., the outer shell is minutely cribrate. The central chamber is small, only 0.025 mm- width, it is surrounded by six subequal rings, at either pole of the test there is an extension of the radial spines for a short distance beyond the chambers, and a delicate, apparently perforate, siliceous