1856.] HARKNESS PERMIAN ROCKS OF SCOTLAND. 259 



but this at present we are hardly in a position to discuss. At one 

 time I was disposed to regard them as triassic, resting the conclusion 

 on the character of the sandstones and the nature of the footprints 

 found on them. 



With regard to the latter, which are principally chelonian, I find 

 these differ in the relative length of the toes from those which occur 

 in the Trias sandstones of Western Point, Runcorn, Cheshire ; and, 

 as Chelonians have existed during several geological epochs, too great 

 importance may be attached to impressions of this Order. Under these 

 circumstances, therefore, the triassic age of these strata is doubtful. 



Sandstone-areas of the upper part of the Annan. — With regard to 

 the two areas which occupy the east side of the River Annan, to the 

 north of the Corncockle area, these consist of breccias with false- 

 bedded sandstone ; and beds of these characters are best seen in the 

 Bell- Craig Linn, about four miles S.S.E. of Moffat. They appear to 

 appertain to the lower strata of the more southern patch ; and the 

 inferior-lying conglomerates are well seen in the course of the Well 

 Burn, from below Heathery Haugh to above Arch-bank. In the 

 most northern area, the sandstone is well exposed at Newton ; and 

 this is probably the lower portion of the false-bedded sandstone which 

 rests upon the breccias, as seen in the course of the Kinnel Bum. 

 It is on the eastern margin of these two areas that we have the beds 

 exposed ; and here they are seen dipping from the Silurians. The 

 western extremity of these patches is not seen, as the low ground is 

 occupied by drift, and by gravel deposited by the River Annan. 

 Where we have the newer strata exposed, they manifest themselves 

 under the same circumstances as in the more southern area, viz. 

 dipping away from the older deposits. 



Sandstone-area of Mitchell-Slack. — As regards the Uttle patch in 

 the course of the Capple Water, below the farm-house of Mitchell- 

 Slack, this is so small that little can be made of it, except that, from 

 its brecciated nature, it appears to have affinity to the lower portion 

 of the Corncockle series. It has a southerly inclination, dipping 

 from the high hills which lie to the north. Its area cannot be made 

 out owing to the drift which covers it, except in the spot before 

 alluded to. This patch is, however, so closely surrounded on all 

 sides by Lower Silurians, that the area occupied by it must be very 

 small. Such a small isolated patch, surrounded on all sides by 

 Silurian hills from 1000 to 2000 feet high, is a matter of considerable 

 interest in connexion with physical geology. 



Thornhill Sandstone-area. — The sandstone-area on the east side of 

 the River Nith, around Thornhill, and occupying the lower portions 

 of the parishes of Morton and Closeburn, is of considerable importance 

 as concerns size ; and its being, for the most part, surrounded by 

 Carboniferous rocks renders this area different in its boundaries from 

 the patches before-described. 



We have better sections exposed here than in some of the other 

 localities occupied by sandstones and breccias ; and we can derive 

 some information from this area which the others do not afford. 



The spot where we have the best sections of the strata of the 



