of the Sandstone of Ayrshire. 285 



ner as the progeny probably of these venerable Borers are, at the 

 present day, piercing the same rock in the sea at Saltcoats. The 

 bore is fully an inch in diameter. The shell still occupies the 

 mouth of the perforation ; and, though now frail, it is distinctly 

 marked by its waved ridges and longitudinal furrows, and the 

 groove running from the hinge to the margin. But what is much 

 more wonderful, at the bottom of the holes which the Pholas has 

 bored, there is a matted tuft of sea-weed {Ulva intestinalis) not 

 petrified, — not converted into peat, — not rotten, — but retaining 

 its sap and form, and texture and reticulations, and even its pale- 

 green colour ! This is not a little surprising. Sir Wm. Hooker, 

 to whom we sent specimens, says that it could not have grown 

 5 feet under ground. From the shells then and from the Ulva, 

 the sea must have been there, though at a period too remote to 

 be now ascertained ; and although the sea is now about three- 

 quarters of a mile distant from the quarry, we can easily credit 

 the tradition that, in ancient times, vessels were accustomed to lie 

 at anchor north of the quarry, and about the place where Ardeer- 

 house now stands (fully a mile from the present high-water mark). 

 Indeed, from various phsenomena that have come under our obser- 

 vation, we have the most thorough conviction that at a period not 

 extremely remote, the half of this parish (Stevenston) was over- 

 flowed by the sea.'^ 



Under the sandstone strata there is a stratum of shale about 

 18 feet in thickness, then comes a coal called " the five-quarter 

 coal," then another stratum of shale, and under it the parrot-coal. 

 The quarry has been worked for upwards of sixty years, and is 

 therefore of considerable extent. The strata very much vary in 

 thickness at difi'erent parts of it. 



The fossils are not confined to any one stratum of the sand- 

 stone, but are found in them all, wherever the sandstone is faulty. 

 I have counted about five strata at the deepest part of the quarry, 

 separated from each other by thin layers of shale, and fossils are 

 found in all these strata, chiefly however where the sandstone is 

 rendered impure by a mixture of greenstone and ironstone. There 

 have been above thirty different kinds of fossils found in this 

 quarry and in the schist connected with the coal : among them 

 many beautiful impressions of ferns, reeds, Stigmarice, Sigillarice, 

 Lepidodendra, and other plants unknown in the present day. Some 

 of these were discovered 70 fathoms (420 feet) beneath the sur- 

 face of the earth. Among the ferns will be found Sphenopteris, 

 NeuropteriSj Pecopteris, &c. The fossils which occur in greatest 

 profusion are the Calamites, which are thus spoken of by Mr. 

 Gourlay at a meeting of the Philosophical Society of Glasgow, on 

 15th February 1843: — (See their Transactions, p. 107.) 



^^ The fossil plants referable to the genus Calamites of Bron- 



