1885.] 



On the Reptiliferous Sandstone of Elgin. 



401 



graduates insensibly into the coarse Reptiliferous Sandstone, which 

 forms a number of courses, each from 3 feet to 4 feet thick, and are 

 exposed to a depth of over 20 feet. The Reptiliferous Sandstone in this 

 pit section exhibits evidence of considerable disturbance ; its beds dip 

 to the north-east at an angle of about 15°, while, at one part of the pit, 

 there are indications, in great slickensided surfaces and a slight dis- 

 placement of the beds, of a small fault. In these upper sandstones 

 remains of a least six reptiles have up to the present time been dis- 

 covered, five of them occurring in one course of stone, while the 

 remaining one came from the bed immediately below. The forms 

 represented in this pit are Hyperodapedon, and another lizard, 

 Dicynodon, and a Dinosaur. 



The characters of the sandstones above the bed of conglomerate are 

 very distinct from those of the sandstones below it. The former are 

 very fine grained and have their lamination very strongly pronounced, 

 exhibiting much false-bedding; w r hile the latter are usually much 

 coarser and seldom show any trace of stratification. The colours, too, 

 are very distinctive, but this is a character upon which it would be 

 unwise to place much reliance. Examined in thin sections, under the 

 microscope, I found that the two sandstones present well-marked and 

 constant differences. 



These facts all point to the conclusion that the Reptiliferous Sand- 

 stone of Elgin passes downwards into a bed of conglomerate, which 

 rests unconformably upon the strata of the Upper Old Red Sandstone. 



During a visit to Sutherland last year, I also obtained evidence that 

 a precisely similar relation in all probability exists between the 

 Triassic rocks and the Upper Old Red Sandstone on the northern side 

 of the Murray Eirth. 



Some years ago Dr. Joass of Grolspie found remains of Holoptychius 

 in the sandstones which crop out in reefs on the shore at some distance 

 southward from that place. Between these reefs of Upper Old Red 

 Sandstone and those of Dunrobin, where I was able in 1873 to 

 identify the Reptiliferous Sandstone and the Cherty rock overlying it, 

 the rocks are wholly concealed. But Dr. Joass showed me masses of 

 a conglomerate which are frequently thrown up by the waves on the 

 Golspie shore, containing yellow and purple quartz-pebbles, and 

 identical in character with the rock of the " pebbly-post " in the 

 Cutties, Hillock Quarry near Elgin. There can be little doubt that 

 the bed from which these fragments are derived lies between the 

 Trias and the Upper Old Red Sandstone of the Sutherland coast. 



The Royal Society long ago testified its sense of the importance of 

 determining the age and relations of the remarkable strata of Elgin, 

 by appointing a Committee and making a grant from the Donation 

 Eund to aid in securing new specimens of the fossils. Seeing, then, 

 that an opportunity offered itself for determining the exact relations 



