18 CATALOGUE OF PHILOSOPHICAL APPARATUS, &c. 



Drawer 1 7. Silurian rocks from the North and East of Scotland Stone- 

 haven, Aberdeenshire Lochaber, Banffshire. 



Drawer 18. Silurian rocks from Oban, West of Scotland. 



Drawer 19. Silurian slates with Orthoceratites from the lake of Silgau in 

 Dalecarnia, Sweden. 



Drawer 20. 



Drawer 21. 



N. B. The above drawers contain specimens from the oldest stratified rocks known in Great 

 Britain ; those from the bottom of the series, such as the Bangor and Skiddaw slates, being 

 destitute of organic remains, and according to my experiments, detailed in the seventh vol. of 

 the Journal of the Chemical Society, devoid also of Phosphoric Acid. If this be the case, it is 

 impossible that any organic remains can ever have existed in the formation, for we know of 

 no animal or plant from the constituents of which Phosphoric Acid is entirely absent. Hence 

 such rocks may be regarded as Azoic, or deposited where no organic beings existed. 



The Lingula, of which specimens occur in Drawer 9, is at once the oldest fossil known, and 

 the one that has extended through the greatest number of formations, having existed alike in 

 the Silurian and in the present eras, and in both cases with scarcely any difference in form 

 or structure ; a fact often alleged in discredit of Mr. Darwin's theory as to the production 

 of new species by natural selection. 



The best authorities to be consulted are Murchison's Silurian System, and Sedgwick's 

 various papers, especially that in the British Association Report for 1853. 



DEVONIAN ROCKS, INCLUDING THE OLD BED SANDSTONE. 



Drawer 22. Slates and limestones with Cyathophylla and various fossils, from 

 the neighbourhood of Plymouth and Exeter. Beekitesf 

 from the triassic Conglomerate, containing fragments and 

 rolled masses of Devonian limestone, near Torquay. 



Drawer 23. Polished specimens of fossil sponges, orthoceratites, and corals 

 from the Devonian limestones, near Torquay. 



Drawer 24. Corals from ditto, also polished. 



Drawer 25 and 26. Old red sandstone with fossil fish, Cromarty, Scotland. 

 [For these rocks consult Hugh Miller's work, entitled Old Red Sandstone.] 



f Beekite is the name given to a variety of which the siliceous matter has collected. See a 



Chalcedony which forms in tubercles, or in sphe- paper by Mr. Pengilly, read before the Geol. 



roidal concretions upon some fossil present in Section of the British Association at Cheltenham, 



the limestone, which constitutes a nucleus round 1856. 



