The Scottish Naturalist. 115 



From this point they may be traced westward for a quarter of a 

 mile, and up the burn of Balmanno Hill for about one-fifth of 

 a mile, when an outcrop of trap puts an end to them. Bal- 

 manno Hill rises to 721 feet; the point of contact of the beds 

 with the trap is perhaps 100 feet above Dron mill, and this 

 mill is about 60 feet above sea-level. Eastward they may be 

 traced beyond the kirk for a short distance, where they form 

 the bed of the burn and then disappear. They are well seen at 

 the back of the mill, and I doubt not the knoll, upon which the 

 kirk and the whole of East Dron is situated, is composed of 

 these rocks. I could not define their exact boundary, either 

 eastward, westward, or to the south ; but that they are local 

 may be inferred from the fact that to the west a bright red 

 Old Red Sandstone is quarried at about a mile distant ; and 

 to the east, to within as short a distance, the Old Red Sand- 

 stone of the Carse of Gowrie approaches ; and the traps of 

 Moncreiffe Hill are a sure indication of its limit on the north. 

 There is no possibility that they are rocks likely to dip under 

 the Old Red. The beds have only a slight dip into the valley, 

 but form a synclinal curve, dipping from east and west at an 

 angle of about 25 . 



Lithologically the beds are argillo-calcareous unstratified 

 sandstones, calcareous shales, several thin seams of bituminous 

 shale, and bands of a pale grey close-grained cuboidal limestone. 

 I would here beg to thank Sir Thomas Moncreiffe for kindly 

 calling my attention to the beds. 



On the first visit, February 1874, I hesitated to pronounce 

 upon them, but expressed to Dr. Buchanan White an opinion 

 that they were Carboniferous. This opinion has been strength- 

 ened by subsequent visits, and I am now as persuaded as I 

 generally dare to be about anything, of their authenticity. 



I have since learned that Dron is somewhat classic 

 ground, that it has been before visited by several eminent 

 geologists, and perhaps even described by one of whom it 

 would be quite irreverent not to speak with the greatest 

 respect, the late Rev. Dr. Anderson of Newburgh, author 

 of "Course of Creation," "Geology of Scotland," "Dura 

 Den," &c I have in several ways seen that Dr. Ander- 

 son did visit Dron. The first evidence was two fragments of 

 stone that I saw in the collection at Rossie Priory, which I 

 felt sure were from Dron. No locality was assigned to them, 

 but one was marked "cypris," the fragment being full of those 



