TRANSACTIONS OF THE SECTIONS. 57 



vegetable life. The upper strata of sandstone, as the section explains, are gray ; they 

 become variegated with red as they descend, and it is only the bottom beds of the 

 quarry that have the dark red colour so common to this formation. 



The fossil footsceps have been found on nearly all the beds of sandstones; on the 

 uppermost small pointed impressions as if from Crustacea, and others resembling the 

 feet of birds. Impressions of Cheirotherium are on the upper strata also, but they 

 are of small dimensions, increasing in magnitude as the beds descend. Referring to 

 the several specimens from this quarry in possession of the Warrington Natural Hi- 

 story Society, and now in their museum, we notice a gray sandstone slab on which 

 are footsteps of Cheirotherium, chiefly varying from |ths of an inch to 1^ inch long, 

 the largest impression being 4 inches in length. The next, a slab of the same colour, 

 has impressions 3 inches in length. Another gray sandstone slab has impressions 4 

 inches in length. And upon a slab of dark red sandstone is one impression 10 inches 

 long, but of peculiar form, as though the foot that made it had been furnished with 

 claws. 



The most remarkable specimens of Cheirotherium from this quarry that I have 

 seen, are in the possession of Mr. John Robson, surgeon, of Warrington. Both are of 

 the deep red sandstone of the lower bed. The largest specimen, a slab of about 20 

 inches diameter, has two footsteps in the usual position in which they are when left 

 by the same animal, viz. the smaller preceding the larger footstep, which is 9^ inches 

 in length. The other specimen is a footstep of 7i inches long, on a slab of similar 

 sandstone. 



Both these beautiful specimens are from impressions that appear to have been left 

 upon a thin stratum of the finest clay, which was so well prepared to receive the mould 

 as to leave a cast so delicate as to give us the texture of the skin that covered the 

 sole of the foot. This appears to have been covered with small papillae, about 100 

 to the square inch in the larger specimen, and about 220 to the square inch in the 

 smaller specimen ; showing that the sole of the foot was furnished with a rough skin, 

 such as might have been expected in a creature that walked upon a sandy shore. 



Notice of Perforations in Limestone. By Dr. Buckland. 



Dr. Buckland laid on the table a slab of limestone from Plymouth, perforated with 

 deep, irregularly rounded holes, which he attributed to the long-continued action of 

 the slime of garden snails {Helix aspersa), and stated that he found litmus paper to 

 exhibit a red tint if these snails are made to crawl over it. The feeble action of a 

 small quantity of acid in their slime, continued on the same parts of the same stone 

 during a long series of years, seems to afford an adequate cause for those effects, which 

 were last year adduced at Plymouth as the work of marine animals, and as affording 

 evidence of a raised beach. On visiting the spot, Dr. Buckland found the slab now 

 exhibited, with several living snails, and also shells of dead snails in the holes. In 

 September 1841, he found similar holes, with shells of a smaller wood snail in them, 

 on the under surface of blocks of limestone in Cumberland, and Mr. Baker has re- 

 cently observed them in the limestone of Cannington Park, near Bridgewater. 



On Recent and Fossil Semi-circular Cavities caused by air-bubbles on the 

 surface of soft clay, and resembling impressions of rain-drops. By Dr. 



Buckland. 



In July 1840, Dr. Buckland first noticed cavities of this kind upon the surface of 

 some desiccated mud, which had been laid in small heaps by the side of the rail- 

 road near Reading; they were mostly of the size of holes impressed by large rain- 

 drops, but could not be referred to rain, because they existed only on certain spots 

 lower than the general surface of the heaps. The origin of these holes appeared to 

 have been the rise of bubbles of air through the bottom of little partial shallow 

 ponds of water on the mud, the general surface of which, from its convex form, had 

 allowed no water to rest upon it. A slab of new red sandstone on the table, from 

 near Birmingham, containing a few impressions of vegetables, was covered with small 

 tubercles in close contact with one another, and apparently caused by the deposition 



