849 NOTE ON THE OCCURRENCE OF A LIMESTONE-FLORA AT GROSE VALE. By W. M. Carne. Instances of the part played by geological formation in* the distribution of species and the formation of plant-coQimunities in New South Wales, have been put forward from time to time, by various botanical and other workers. So far as the writer is aware, no record has yet been published dealing with the effect of a lime-deposit on vegetation. The present note deals with an interesting, though small, patch of vegetation occurring on an outcrop of a limestone at Grose Vale, Hawkesbury District. The deposit is to be found below Box Hill, and is followed by the Horseshoe Bend Road, which, running N.E. and S.W., joins the main Kurrajong and Grose Vale Roads. It is on the eastern slope of the hill, which curves to form a natural amphitheatre sheltering orchards and other cultivated areas. At about 100 yards from the Grose Vale end, and following the road for about half a mile, nearly to what is known as Lookout Hill, is the outcrop, with its vegetation, which is so distinct as to be noticeable against the hillside from several miles away. Another small deposit, denuded of timber, occurs near the church, about half a mile from Kurrajong Road. The deposit is about 800 feet above sea-level, and about 8 miles by road from Richmond. The dense growth of trees, entangled with many creepers, and the absence of Eucalypts, resembles that of the luxuriant gully-brushes of the eastern slopes of Kurrajong Rang(); or, perhaps, more nearly, those on volcanic soils, such as at IMountain Lagoon, Mount Wilson, or even of the Illawarra slopes. Above the road, this vegetation extends nowhere more than 20 yards, while, on the steep slope below, its width has been much greater, probably owing to the soil having been washed down from the outcrop
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