246 Mr. Weaver on Floetz Formations. [Oct. 



tracts with a transition, or with a primary country, is found to 

 vary, move or less, in a corresponding manner, in its composition 

 and structure. It may be said to be generally free from organic 

 remains ; and if such appear at all, they are almost wholly of 

 vegetable origin, and chiefly found where the sandstone is adja- 

 cent to limestone, slate-clay, or coal. 



Of the organic remains met with in the carboniferous lime- 

 stone, I confine myself chiefly to the notice of fish and trilobites, 

 as being comparatively of rare occurrence in that formation. 

 Impressions of fishes, accompanied with shells, are found in 

 the limestone, which forms a part of the lower beds of the coal 

 basin near Old Cumnock, in Ayrshire * Small teeth of fishes 

 occur likewise in the limestone that forms part of the upper por- 

 tion of the coal series in Scotland.f And palates and bones of 

 fishes are met with in the Bristol limestone,:}: which, with the 

 intervention of a belt of sandstone and sandstone conglomerate, 

 supports the contiguous coal field of Somersetshire and South 

 Gloucestershire. 



I found trilobites three years since in the Mendip limestone, 

 and I am informed that they have been met with latterly in the 

 limestone near Dublin. Mr. Greenough notices their occur- 

 rence, also, in the shale accompanying the limestone in Holy 

 Island, on the Northumberland coast. — (G. M.) 



Trilobites have been found likewise in the clay ironstone of 

 the coal formation in Shropshire ; besides terebratulites, and the 

 productus scabriculus. Winged anomites are met with in the 

 shale of the Killenaule coal district in Ireland ; § and in that of 

 Linlithgowshire, in Scotland, four species of orthoceratites are 

 found, one of which accompanied by six other distinct species, 

 occur, also, in the carboniferous limestone of that tract. |[ 

 Orthoceratites, it is well known, occur in the Derbyshire moun- 

 tain limestone ; also, in that of Yorkshire, Mendip, and Bristol, and 

 in Ireland. And ammonites are met with in limestone nodules, 

 and in clay ironstone, and terebratulites in limestone and sand- 

 stone, all imbedded in the slate clay of the coal formation in 

 England.** 



Let us now direct our attention to the Continent. 



In Germany. — In that country, also, it may be remarked of 

 the old red sandstone in general, that, wherever it occurs, its 

 composition is found to vary, accordingly as, in the course of its 

 extent, it comes in contact with, and reposes upon, differently 

 constituted transition or primary tracts. The formation may 

 also be said to be generally free from organic remains. And in 



* Dr. Boue, Essai Geologique sur l'Ecosse, p. 172. f Ibid. p. 195. 



$ Dr. Bright in Geolog. Trans, vol. iv. p. 198 and 200. 



§ Geol. Trans, vol. v. || Dr. Fleming in Atinah of Philosophy, vol. v. 



•• Sowerby's Mineral Conchology . 



