pened at the period when a decided change was taking place in the conditions which determine the forms of life upon the globe.
| 1. Retepora flustracea. Phillips. |
| 2. Mytilus acuminatus. Sowerby. |
| 3. Avicula gryphaeoides. Sedgwick. |
| 4. Axinus obscurus. Sowerby. |
| 5. Producta horrida. Sowerby. |
All these are from the magnesian limestone of Durham and Yorkshire.
The fauna of the magnesian limestone in England has been fully treated by King[1], who presents in a synoptic table the following summary of British and foreign species. (See table at top of next page.)
In regard to the Reptilia we should prefer to omit the British fossils (Thecodontosaurus and Palæosaurus) as really belonging to a triassic conglomerate.
The plants of the Permian system have been examined by Morris and others. They are in a considerable degree marine; but a certain number of ferns, lopidodendra, and calamities, are identical with, or else very nearly allied to, known carboniferous species.
The table which follows was drawn up as the result of the labours of Murchison, Dr. Verneuil and Keyserling, in 1844. (Geol. Proceedings.)
- ↑ Trans. of Palæontol. Soc. 1850.
