IXXX PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



In this interesting description of a district carefully examined, 

 the disappearance of the graptolitic and anthracitic beds on the 

 south side of the axis in Dumfries- shire is a very remarkable fact; 

 for, though in following out laterally a series of beds it is neither 

 unusual nor unnatural to find one or more of its members thin out 

 and disappear, it is certainly very curious to find a whole series thus 

 abruptly cease without any apparent physical cause for their disap- 

 pearance. Speculation on early animal life must always be full of 

 interest when based on carefully observed facts, and leading us, as 

 in this case, to recognize in the state of nature, at an epoch be- 

 yond calculation remote, a prototype of the state of nature as we 

 now see it. 



Another paper by Professor Harkness, on the " Sandstones and 

 Breccias of the South of Scotland subsequent to the Carboniferous 

 epoch," next demands our notice ; but, as I have in my possession a 

 notice of this paper by Mr. D. Sharpe, in which he endeavours to 

 explain the curious converging dip of the strata in the Corncockle 

 district always from the older rocks, which do not exhibit the same 

 phsenomenon, and towards a central area, on a bold hypothesis, 

 highly characteristic of our late President, and quite diiferent from 

 Professor Harkness' s supposition of a subsidence within a limited 

 area, somewhat like the hole of a crater of subsidence, by which 

 the previously horizontal strata had been dragged down, and thus 

 caused to converge or dip towards the same centre, I have thought 

 it desirable to preserve it for the Society. 



Professor Harkness, Mr. Sharpe observes, has minutely described 

 several of the isolated patches of Red Sandstone occurring in the 

 upper parts of the valley of the Annan, and in the upper and lower 

 parts of that of the Nith, in the great chain of slate-rocks of the 

 South of Scotland ; one of which has long been celebrated for the 

 foot-prints of Reptiles found on the sandstones of Corncockle Muir. 

 The detail with which Mr. Harkness describes these deposits enables 

 us to judge fully of their nature, and his observations have led me 

 to a very diiferent conclusion as to their origin, from that which he 

 has himself formed. He starts by stating that the beds in question 

 must be separated from the sandstone of Annan (east and west of 

 the mouth of the Annan River), which he regards as a prolongation 

 of the Triassic sandstone of the country around Carlisle, and in which 

 there are no breccias made up of angular fragments. 



Having thus disposed of the great tract of Red Sandstone of 

 Annan, the Professor enumerates six other detached patches of sand- 

 stone, viz. the Corncockle Muir area on the upper part of the Annan, 

 that near Moffat, another to the north, also in Annan Dale, one on 

 the Capple Water, that on the Nith near Drumlanrig, and the still 

 larger area around Dumfries, all of which the author considers to 

 be the remaining portions of a once widely-spread deposit of sand- 

 stone, of which the greater part has been removed by denudation, 

 and which he refers to the Permian period. 



These various deposits have many features in common : they 

 consist principally of red sandstones with their beds crossed by 



