548 PAL-EONTOLOGIGAL REPORT OF GEOLOGICAL SURVET. 



ted by a thin layer of sulpburet of iron and charcoal. It is topped by 

 the black slaby shales, with great abundance of shells, and some re- 

 mains of fishes; and above it, has a soft calcareous rock, also full of 

 beautifully preserved shells, all species characteristic of this coal. Near 

 Curdsville, opposite this "place, on Green river, in Henderson county, 

 No. 11 coal has been worked, and is here called Cook's upper coal. The 

 coal, four feet thick, has a clay parting; its black shales are full of 

 shells, as at Bonliarbour,andit is covered by two beds of limestone, sepa- 

 rated by a bed of coal-dirt and fire clay, six inches thick. The infe- 

 rior bed of limestone is full of shells, but the superior one is black and 

 without remains of fossils. 



Coal No. 12. The general features of this coal recall the same ob- 

 servations as for No. 10. Its formation has followed too near that of 

 No. 11. It is an unreliable bed, as well for its thickness as for its 

 position. It sometimes comes so near No. 1 1 , that it looks like a part 

 of it, and sometimes it is. found twenty or thirty feet above it. Its 

 palaeontological characters are well marked by an abundance of remains 

 of fossil fishes, especially large scales, and large (mostly double) teeth. 

 In Nos. 9 and 11, the remains of fishes belong only to very small 

 species; in this they are mnch larger. The doulle teeth, found in 

 abundance at Airdrie, are of a peculiar structure, viz : divided into two 

 hooked points, about half an inch long, diverging from the base. 



Exclusive of its fossil remains, coal No. 12 is easily identified by 

 the composition of its coal, which is mostly a dirty, rashy, coaly mat- 

 ter, a compound of flattened Stigmaria, Catamites, and some scarce 

 Sigiltaria, well preserved in their outlines. Coal and shales are cov- 

 ered by a black band, or bed of calcareous iron stone, passing to a 

 black limestone, which sometimes takes its place. This limestone is 

 not fossiliferous, as far as has yet been observed. 



Airdrie, Mulilenhurg county, is the first, and truly the only place, 

 where we had a good opportunity of studying No. 12 coal. It is 

 opened here for the black band from which the material is supplied to 

 C. H. Alexander's furnace. The bed of coal about four feet, has two 

 to three feet of coal-rash, apparently entirely formed of Catamites, Stig- 

 maria, and Sigiltaria. I could not find a Lepidodendron among those 

 vegetable remains. Below the ccal^ash there is one to one and an 

 half feet good coal. The shales, one foot thick, are parted by the 



