1S15.] On the Old Silver Mine in LinUthgowshire. 119 



name of the Hllderstone Hills. Cairn-paple, or Cairn-naple, the 

 highest of these hills, rises 9S0 feet above the level of the sea, and 

 commands an extensive prospect of the surrounding country. The 

 summit is flat, and is composed of green-stone, in many places 

 passing into basalt and vvacke. 



The base on each side consists of rocks having the same dip and 

 direction, and belonging to the Independent Coal Formation. At 

 the western base tliere are many valuable beds of black coal and 

 sand-stone, and at the eastern base there are extensive strata of 

 lime-stone. These all stretch to the north-east, and have a westerly 

 dip. The strata of lime-stone form a bed upwards of 30 feet in 

 thickness, and are covered with beds of sand-stone, slate-clay, and 

 clay-iron-stone. In these the vein is situated which is stated to have 

 produced at one time a considerable quantity of lead and silver. 



The lime-stone is of a blackish-grey colour, of various degrees of 

 intensity. Its lustre is in general glimmering, often glistening, and 

 even shining, but seldom dull. The compact fracture which it 

 exhibits is in general fine splintery, often conchoidal, and some- 

 times earthy. It rarely occurs with a small granularly foliated 

 fracture.* When the stone contains many petrifactions of entro- 

 chites, the foliated fracture is often conspicuous. It is opake, or 

 very faintly translucent at the edges. 



The lime-stone contains many irregular masses of flint, and the 

 same mineral not unfrequently occurs in thin beds, thus occupying 

 . the same place in compact lime-stone which quartz is often observed 

 to hold in granular lime-stone. The petrified remains of marine 

 animals frequently present themselves in this rock. The teeth of 

 fishes, particularly the shark, the spines and portions of the crust of 

 echini, and fragments of the tnlobile of Mr. Parkinson, are but 

 rarely found. The remains of corals and shells are more abundant. 

 The corals belong chiefly to the generaftaigia, millepora, eschara, 

 orbitoUtes, and lubipora. The shells are principally the remains of 

 acephalous moUusca, some of which may be referred to the follow- 

 ing established genera : pinna, modiola, cnrbula, terebratulaj 

 gryphcea, and productm. There are likewise a few shells belonging 

 to genera in the ccphalous order of mollusca. Thus there are 

 species of the genera turbo, inelania, 7iaiiiilus, ammonites, and 

 vrihocera. In the month of May last I transn)itted to the VVer- 

 nerian Society a description of ten species of orthoceratites from the 

 strata of this district, and chiefly from the bed of lime-stone above- 

 mentioned. This establishes the fact of their occurrence in the 

 Independent Coal Formation, and thus proves that they are not 

 peculiar to the lime-stones of the transition period. This point had 

 been ascertained in Scotland upwards of 20 years ago by the late 



• One >|>rcinii>i) of pranularlj foliated lirae-sione from lhi« bed ii of a greyUk 

 black culiiiir, and is miirli imprrgrutcd with bituminous mntCer, asmftll porlioD of 

 wliich pcrvadcii tlie kIioIc bed. 



