46 



THE GEOLOGIST. 



lections, have enabled Professor Huxley to decide that, -with the exception of tlie 

 Tderpeton, all these casts, scales, and bones belong to the Reptile Stagonolepis 

 Rohertsonii. 



Sir Roderick having visited the quarries in the coast-ridge, from which slabs 

 with impressions of reptilian footmarks had long been obtained, induced Mr. G. 

 Gordon to transmit a variety of these, which are now in the Museum of Practical 

 Geology ; and some of which were exhibited at the meeting. 



After reviewing the whole succession of strata from the edge of the crystalline 

 rocks in the interior to the bold cliffs on the sea-coast, the author has satisfied 

 himself that the reptile-bearing sandstones must be considered to form the Upper- 

 most portion of the Old Red Sandstone, or Devonian group ; the following being 

 among the chief reasons for his adherence to this view. 



1st. That these sandstones have everywhere the same strike and dip as the 

 inferior red sandstones containing Holoptychii and other Old Red Ichthyolites ; 

 there being a perfect conformity between the two rocks, and a gTadual passage 

 from the one into the other. 2dly. That the yellow and light colours of the upper 

 band are seen in natural section to occur and alternate with red and green sand- 

 stones, marls, and conglomerates low down in the ichth.yolitic series. Idly. That, 

 whilst the concretionary limestones called " Cornstones" are seen amidst some of 

 the lowest red and gi-een conglomerates, they reappear in a younger and broader 

 zone at Elgin, and re-occur above the Telerjoeton-sandstone of Spyuie Hill, and 

 above the Stagonolepis-sandstone of Lossiemouth ; thus binding the whole into 

 one natural physical group. 4thly. That, whilst the small patches of so-called 

 " Wealden," or Oolitic strata, described by Mr. Robertson and others as occurring 

 in this district, are wholly uncomformable to, and rest upon, the eroded surfaces 

 of all the rocks under consideration, so it was shown that none of the Oolitic or 

 Liassic rocks of the opposite side of the Moray Frith, or those of Brora, Dunrobin, 

 Ethie, &c., which are charged with Oolitic and Liassic remains, resemble the 

 reptiliferous sandstones and " Cornstones" of Elgin or their repetitions in the 

 coast-ridge extending from Burgh Head to Lossiemouth. 



Fully aware of the great cUfiiculty of determining the exact boundary line 

 between the Uppermost Devonian and Lowest Carboniferous strata, and knowing 

 that they pass into each other in many countries, the author stated that no one 

 could dogmatically assert that the reptile-bearing sandstones might not, by future 

 researches, be proved to form the commencement of the younger era. 



Sir Roderick concluded by stating, that the conversion of the Sfagonolejns into a 

 reptile, of high organization, but of nondescript charactef, did not interfere with 

 his long-cherished opinion— founded on acknowledged facts — as to the progi'essive 

 succession of great classes of animals, and that, inasmuch as the earliest Trilobite 

 of the invertebrate Lower Silurian era was as wonderfully organized as any living 

 Crustacean, so it did not unsettle his belief to find that the earliest reptiles yet 

 recognised, the Stagonolepis and Telerpeton, pertained to a high order of that 

 class. 



[The memoir was illustrated by geologically-coloui-ed charts of the Admhalty's 

 Hydrographic Survey of the Coast, extending from the Orkney Islands to Banff- 

 shire (which, in the want of any accm'ate maps, fortunately gives the outlines of 

 the coast and a few miles inland), and by transverse sections showing the succes- 

 sion and relations of the strata, as Avell as munerous organic remaiiis from the 

 collections of Mr. P. Duff", Mr. Gordon, the Elgin Museum, the Museum of 

 Practical Geology, and the Geological Society's Museum.] 



3. " On the Stagonolepis Rohertsonii of the Elgin Sandstones ; and on the Foot- 

 marks in the Sandstones of Cummingston." By Thomas H. Huxley, F.R.S., 

 F.G.S., Prof of Nat\u-al History, Government School of Mines. 



The unquestionable remains of Stagonolepis Rohertsonii, which have hitherto 

 been obtained, consist partly of bones and dermal scutes, and partly of the natural 

 casts of such parts. The former have been obtained only at Lossiemouth, and are 

 (•oni})aratively few in number ; the numerous natural casts, on the other hand, 

 have all l)cen procured at the Findrassie Quarry, in which no bones or scutes in 

 their original condition have been discovered. 



The considernblc scries of remains exhibited to the Society did not embrace all 

 tliose wliich had been sul)jeeted to examination, but contained only a selection of 



