506 Proceedings of the Royal Physical Society. 



extra number of pieces of scorpion and Eurypterid skin, 

 excellently preserved, with all the peculiarities of structure 

 and ornament which distinguish the two families. This coal 

 is the middle one of three, which occur in a bed of fireclay 

 or shale 8 or 10 feet in thickness which lies between two 

 beds of sandstone, the lower of which overlies a thick bed of 

 volcanic ash. The fireclays represent old soils, and the coals 

 the plants which grew therein, and the pieces of scorpion 

 and Eurypterid skin the animals that lived and hunted 

 for prey beneath their shade. The numbers of these animals 

 may be roughly guessed from the fact that from a small 

 bagful cut out from the outcrop, in cubic bulk not more than 

 half a cubic foot, several dozen pieces of Eurypterid skin 

 were derived. If so small a portion of the bed yielded so 

 many, then the quantity in the whole must be incalculable 

 by any ordinary enumeration, and can be only expressed by 

 some of these figures of speech, such as the hairs of the head, 

 expressive of multitudes which no man can number. The 

 strata exposed in Shear Burn must lie deep down in the 

 Calciferous Sandstones. 



(3.) Shore West of the Pans, 1 mile W. of Crail, Fife.— 

 The remains of scorpions occur here in a plant-bed in the 

 middle of a thick bed of clayey shale which intervenes 

 between two thick beds of laminated sandstone. The plant- 

 bed is about 5 or 6 inches in thickness, and is composed of 

 thin layers of clay, separated by partings of vegetable cUlyris 

 crushed flat, and generally not recognisable, but in some 

 instances we can say that is a sphenopteris and that a 

 lepidodendron. The pieces of scorpion and Eurypterid skin 

 are found lying spread out flat among the blackened d6bris. 

 They are easily got by simply crushing the matrix sideways, 

 when the clay crumbles into dust, and the pieces of scorpion 

 and Eurypterid skin being comparatively tough, drop out in 

 bits, which are readily recognised by their markings or 

 structure. These clays and sandstones have been laid down 

 in calm, undisturbed lakes on land, or if their waters were 

 troubled at any time, it was only by light winds gently 

 rippling the surface. The thin laminations betoken a fre- 

 quently interrupted, yet iu the main continuous, deposition 



