Obscure Markings upon an Old Red Sandstone. 163 



The communications read were as follows : — 



I. On some Obscure Markings upon an Old Red Sandstone Slab at 

 Mill of Ash, near Dunblane. By the Rev. Robert Hunter, late of 

 Nagpore. 



The large slab, half of which has been laid upon the table, 

 is a micaceous flagstone, from a fissile layer, a few inches thick, 

 with a more compact sandstone or gritstone both above and 

 below it, and at no great distance from a trappean effusion. 

 It would seem to belong to the lowest or Ceplialaspis zone 

 of the Old Red Sandstone. The Rev. Walter Smith, of Free 

 Roxburgh Church, in this city, when with me last August, in 

 a quarry at Mill of Ash, observed some of the markings on a 

 projecting ledge of stone, and that clay and the next he and I 

 laid the rock bare for a space of six feet in length by five in 

 breadth, and came on about 150 of the markings. More 

 recently, the slab was raised, and the Rev. Mr Paterson, of 

 Dunblane, kindly consented to take the trouble of having it 

 packed and forwarded to Edinburgh. The impressions are of 

 two sizes. Their form is elliptical, with a raised border, one 

 side being in much bolder relief than the other ; and it is im- 

 portant to note that the raised margins all correspond in posi- 

 tion with each other. Within, and separated from the elevated 

 border by a channel, there is occasionally a raised central 

 space, with a tendency to longitudinal furrowing. The longer 

 axes of the ellipses all point nearly in the same direction. 

 They are arranged with some regularity, though at times two 

 are in such close contact as to form an eight figure, and, more 

 rarely, a couple of these eights uniting have constituted a rude 

 cross. Mr Page possesses some curious impressions from 

 Ardoch, a few miles north of Mill of Ash, but judging from 

 some figures he hastily drew for comparison, they are of forms 

 entirely different from those now described. It is difficult to 

 say whether the markings are of organic or inorganic origin. 

 The hypothesis on the subject which most naturally arises, 

 and being expelled has a tendency to return, is, that they are 

 footprints of some animal. There are, however, very formidable 

 objections to this view. Nor can they well have been formed 

 by pebbles, or by the impressions of ganoid scales, for sub- 



