Peculiar U-shaped tubes in sandstone near Crawfurdland Castle and in Gowkha Quarry, near Killwinning

Extract. This 250-word extract was created in the absence of an abstract. Two years ago when examining the sections exposed in the Crawfurdland Burn, near Crawfurdland Castle, 2 miles north-east of Kilmarnock, I observed on certain parts of the sandstone rock a number of peculiar U-shaped markings, with which I was not at all familiar. A portion of the sandstone containing one of these markings, which I detached from the rock, was placed in the Hunterian Museum, Glasgow, and Mr. Young informed me he had never seen any similar markings before, suggesting that I should send a note on them to the Society. Lately, when in the Crawfurdland district with Mr. Carrick, I made a more minute examination of the beds, and found the section exposed on the west side of the Crawfurdland Burn to be as follows: The beds dip to the south as shown on section [Plate No. X.], and the U-shaped markings are first seen here and there in the top part of bed C. The animals which formed the markings had commenced to dig into what was probably for the time being the bed of an estuary, and continued to live in that position till further sedimentation buried up their homes, when they or their descendants again began to dig and form fresh habitations in the overlying bed. In the section at Crawfurdland this process has been repeated many times. Bed B is literally crowded with them, and on breaking off some of. the more shattered parts of the rock-face, the markings are seen to have the uprights