Page:A Voyage of Discovery and Research in the Southern and Antarctic Regions Vol 2.djvu/437

Rh Town, I visited a quarry of yellow travertin-limestone, a tertiary deposit coloured by oxide of iron and much decomposed, dipping W.S.W. at an angle of 50 degrees, and abounding in impressions of leaves of Dicotyledonous plants of an extinct flora. Two kinds occur beautifully preserved; but I could discover no traces of shells, although two extinct species, a helix and bulimus, are sparingly imbedded in a similar deposit which appears on the opposite side of the Derwent, at the head of Lindisfern Creek, about two miles from Hobart Town. The limestone is of the same yellowish colour, but more indurated in texture, and has been quarried to the depth of seventy or eighty feet. The shells are found in the upper layer, and both leaves and stems in the lower portion.

The locality of Mount Wellington, which rises to the height of four thousand one hundred and ninety-five feet, on a basis of sandstone, capped, by basalt, two thousand feet in thickness, abounds in organic remains. The sandstone with which the houses in Hobart Town are built, is very soft when first quarried, but hardens on exposure to the atmosphere. In some places it is micaceous, with dark arborescent markings, in others enclosing hard ferruginous-coloured nodules, of various sizes, usually of flattened spheroidal form.

The following species of fossils are found in this locality. Polyparia (corals), Stenopora Tasmaniensis, S. ovata, Fenestella fossula, F. ampla, F. internata, and Hemitrypa sexangula.

Conchifera (bivalve shells), Pecten squamuliferus, P. Fittoni. Brachiopoda,—Spirifera Tasmaniensis, S. subradiatus, Producta subquadratus, and P. brachythserus. Terebratulæ are also met with, and a species of Cypræa (cowrie) has been found in sandy alluvium. The woods on the slopes of Mount Wellington are ornamented with the elegant and magnificent Tree fern.

A large bivalve shell, Pachydomus globosus, occurs in the argillaceous formation at Risdon.