ME. J. W. KIRKBY ON PERMIAN FISH AND PLANTS. G7 



associated with or passing into strata of conglobated or botry- 

 oidal and very friable white limestone ; this group is the 

 "White Stone" of the Fulwell quarrymen. Immediately be- 

 low is about three feet of dark grey, highly crystalline, and 

 conglobated limestone, with beautiful (metastatic) crystals of 

 calc-spar, and crystalloids of limestone; this is named tbe "Black 

 Shell." Underlying it is generally a bed of soft friable limestone 

 with conglobations ; and then follows from twenty to twenty- 

 five feet of thick-bedded crystalline and concretionary limestone, 

 which, from its peculiar structure, is termed the "Honeycomb 

 Limestone or Main Stone." Separated from the Main Stone by 

 about two feet of conglobated limestone, follows nine feet of 

 white or yellowish, very soft and friable limestone, which is the 

 great "Marl Bed" of the quarrymen. Under it is about nine 

 feet of thinner-bedded, often laminated, compact, yellow or 

 brown limestone, called the "Dun Stone." This is underlaid 

 by eight feet of highly concretionary and crystalline, coralloidal, 

 and laminated limestone, designated the " Grey Stone." Imme- 

 diately under this is two feet of laminated limestone, which I 

 have already noticed as having yielded most of the fish-remains ; 

 on this account I propose to call it the Fulwell Fish-bed. About 

 eight feet of limestone underlies the fish-bed, the upper portion 

 being concretionary and laminated, and the lower laminated and 

 argillaceous, the most inferior stratum passing into a bed of 

 yellow-brown and white, laminated marl and clay, one foot thick. 

 The laminated marl rests upon the Middle Limestone, which at 

 Fulwell assumes its pseudobrecciated phase, being light-coloured, 

 friable with hard cherty concretions, unstratified, and unfos- 

 siliferous. 



The accompanying section (fig. 1) of the Fulwell limestone 

 will, perhaps, render this account easier of comprehension ; and 

 the sequence of strata indicated may be seen, either wholly or in 

 part, in the various quarries at Fulwell Hill, but more particu- 

 larly in the old quarry of Sir H. Williamson. The basal beds of 

 the Upper Limestone, and their junction with the Middle Lime- 

 stone, are well exposed in the cutting on the North-Eastern 

 Railway, at Fulwell. 



