Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/19

 direction. It appears therefore that their dip is not affected by the limestone. It is a circumstance however too well ascertained to admit of a doubt, though difficult to be accounted for, that the coal is deteriorated in quality where covered by the limestone.

Galena is the only metallic ore that I have observed in this limestone. It has been found in small strings at Whitby quarry, Clacks-heugh Blackhall-rocks, Ryehope, and amongst the rocks below Tynemouth castle: at the latter place calcareous spar is the matrix.

The crystallized fossils are small crystals of calcareous spar, formed in groups of acute three-sided pyramids; sometimes white and opaque; at other times yellowish or hair brown and translucent, lining cavities of buff marly limestone; from the cliffs near South Shields and Marsden.

Botryoidal masses of fetid limestone devoid of magnesia, in balls varying from the size of a pea to two feet in diameter, imbedded in soft, marly, magnesian limestone, are found at Hartlepool, in the quarry at Building hill, near Sunderland, and on the sea-coast a mile or two north of Monk Wearmouth. These balls are radiated from the center, their colour hair brown, fracture shining, cross fracture splendent approaching to vitreous: white calcareous spar is frequently observed within them. See Sowerby, Brit. Min. tab. 38.

Stalactitical fetid limestone. See Sowerby, tab. 148. These cellular masses resemble corallines, and are also met with in the marly limestone above described.

Organic remains are rarely met with in this limestone. The most remarkable one was found in a quarry at Low Pallion. It is the impression of a fish, which appears to belong to the genus Chætodon.