MR. J. W. KIRKBT OK PERMIAN FISH AKC PLANTS. 69 



The limestone of the fish-bed in the new quarry, Fulwell, 

 though difficult to describe in precise terms, on account of its 

 liability to structural changes, is almost invariably laminated or 

 slaty, the lamina? usually showing repeated alternations of crystal- 

 line, earthy, and compact textures. The crystalline laminae are 

 generally grey or brown in colour, and the earthy and compact 

 laminae of various shades of yellow. A band of soft and rather 

 friable light yellow limestone runs through the centre of the bed. 

 In some places the limestone of this bed becomes generally more 

 highly crystalline and somewhat concretionary in character ; 

 when this occurs, the plane surfaces are rough and more or less 

 irregular. Otherwise the surfaces of the lamiwe are usually 

 smooth, forming a fine matrix for the fossils they enclose. 



In the old quarry the bed decreases somewhat in thickness, is 

 not so regularly laminated, and is softer and more earthy than in 

 the new quarry. 



At Marsden, the limestone which has yielded me fish-remains 

 is soft, yellow, and finely laminated, being, in fact, the well- 

 known "flexible limestone" of geologists. 



In the fish-bed of the new quarry, and wherever else these 

 fossils occur, the specimens almost invariably appear to have 

 belonged to perfect individuals, or, at least, the dermoskeleton, 

 fins, and bones of the head have been unimpaired up to the period 

 of deposition, though instances of distortion by subsequent com- 

 pression are not unfrequent. The specimens are found on the 

 surfaces of the laminae, usually slightly in relief. They almost 

 invariably retain the finely enamelled surface of the original 

 ganoine, and are of a brown colour. Most of the examples found 

 present a lateral view, with the dorsal, anal, and caudal fins out- 

 spread, and with the trunk uncontorted; examples with the 

 trunk bent upon itself, or what is usually termed contorted, are 

 comparatively rare. Individuals showing the dorsal and ventral 

 aspects occasionally occur. Besides the scales, cephalic bones, 

 and fin-rays, the interspinous bones of the fines are sometimes 

 preserved ; and very rarely traces of the vertebral processes. 

 The specimens are sparingly distributed in the bed, occurring 

 generally as isolated individuals ; still, a pair of individuals, and 



