138 Reports and Proceedings. 



them belonged to the horse, about one-third smaller than the average 

 size, but probably of the common species — Equus cahallus. Two 

 others were portions of the horns of the extinct " Irish deer " 

 — Megaceros Hihernicus. These remains were found in the upper 

 portion of a thick bed of laminated clay, which at this part of 

 the valley is mixed up with so much vegetable matter that it presents 

 quite a peaty character. They lay on the same horizon, and near to 

 the spot where the skull of the Bos primigenius was found some time 

 ago. The depth at which they occurred below the old surface of the 

 valley is nearly 20 ft., but recent cuttings seem to show that part of 

 the overlying bed is the result of slips of earth and Boulder-clay 

 from the hill-side, over deposits formed in the bottom of an old lake.^ 

 This appears to be the second instance in which the "Irish deer" has 

 been found in Scotland. Mr. Young also stated that this seems to 

 be the first recorded instance in which the remains of the horse have 

 been found associated with the large extinct mammals that roamed 

 in the valleys of Scotland in Post-Pliocene times. — Mr. Eobert 

 Craig then read a paper on " Sections of Boulder-clay in the North 

 of Ayrshire, and at the railway cutting in Cowdonglen, near Croft- 

 head, Neilston." 



II. Ordinary meeting, 2nd December, 1869, Mr. John Young, 

 Vice-President, in the chair. — Mr. J. Wallace Young read a paper 

 " On the Application of the Microscope to the Examination of Eock- 

 Structure and Composition." The author advocated the microscopical 

 examination of rocks. By this method Geologists would be enabled 

 to distinguish rocks of igneous from those of sedimentary origin. A 

 number of sections of rocks were exhibited by Mr. J. W. Young, in 

 illustration of his paper. 



The following three papers were then read by Mr. James Thomson, 

 F.G.S. :— (1) " On the Teeth of Pleurodus." Mr. Thomson ex- 

 hibited a slab of the Airdrie blackband ironstone, one of the sur- 

 faces of which, covered with shagreen, contained upwards of sixty- 

 five teeth, belonging to what have hitherto been regarded as three 

 distinct species of Carboniferous fishes, viz., Pleurodus Banhinii, 

 P. affinis, and a Helodus ; but from sections prepared, which were 

 shown under the microscope, and from investigations which he had 

 made regarding the teeth and dermal structure of some of the living 

 rays to which they are allied, he was of opinion that the three 

 varieties of teeth on the slab all belonged to one species only. 

 (2) " Note on the Discovery of Plants in the Schists of Argyllshire." 

 Mr. Thomson exhibited specimens of two different plants which he 

 had discovered in a dark-grey arenaceous shale near Campbeltown. 

 One, marked with longitudinal parallel lines, resembles Sigillaria; 

 the other Calamites of the Coal-measures. Mr. Thomson said he 

 believed these plants to be the first traces of organic remains yet 

 recorded from the schistose rocks of the British Islands, hitherto 

 deemed unfossiliferous. (3) " On the Teeth and Dermal Structures 

 found associated with CtenacantJius." 



' See Mr. James Geikie's paper in the Gbol. Mag. for February last, p., 53. 



