Silurian Conodonts.—

Conodonts belonging to three genera are known from Australia. They are all from the Silurian of the Bowning District, near Yass, New South Wales, and are referred to the genera Eunicites, Oenonites and Arabellites.

Fig. 82—FOSSIL WORMS.

A—Trachyderma crassituba, Chapm, Silurian. South Yarra, Vict.
B—Cornulites tasmanicus, Eth. fil. Silurian. Heazlewood, Tas.
C—Spirorbis ammonius, M. Edwards, var. truncata, Mid. Devonian. Buchan, Victoria
D—Torlessia mackayi, Bather. ? Trias. Mt. Torlesse, N. Zealand.

Palaeozoic Errant Worms.—

The wandering Worms (Polychaeta errantia) are also recognised by their impressions, trails, borings and castings. Burrows formed by these worms are seen in Arenicolites, found in the Silurian sandstone of New South Wales, near Yass, and in the Carbopermian (Gympie Series) near Rockhampton, Queensland. The membranous-lined burrows of Trachyderma (T. crassituba), occur in some abundance in the Silurian mudstones in the neighbourhood of Melbourne, Victoria ([Fig. 82 A]). The genus Trachyderma is common also to Great Britain and Burmah, in beds of the same age.

Worm Tracks.—

Some of the curious markings on the Carboniferous sandstone of Mansfield, Victoria, may be due to worm trails and castings, especially since they are associated with sun-cracks and ripple-marks.

Sedentary Worms.—