EXPLANATION OF THE PLATES. 



Plate XL 

 Fossil fish: p. 118. 



Plate XIL 



Fig. 1. Fossil fish; genus not determined : p. 118. 



Fig. 2. Inner part of the scales magnified. 



Fig. 3. Fossil fish of the same genus with the preceding, but apparently of a different 



species. 

 Fig. 4. represents part of the scales magnified. 



N.B. All the preceding fossils, commencing with Plate VIII., were found in 

 the marl-slate of Midderidge and East Thickley*. 

 Fig, 5. Unknown coralline body. 

 Fig. 6, Retepora virgulacea : p. 120. 

 Fig. 7. Internal cast of an unknown Coralline. 

 Fig. 8. Retepora flustracea : p. 120. 



PLATES XIII. XIV. XV. XVI. XVII. 



Illustrate the memoir by Professor Sedgwick and Mr. Murchison on the Structure 

 and Relations of the Deposits between the Primary Rocks and the Oolitic Series 

 in the North of Scotland. 



Plate XIII. 



Sketch of a Geological Map of the North of Scotland. The object being simply to 

 carry the eye to the range of the secondary deposits, no subdivisions have been 

 attempted. Thus in the red colour are included all the primary formations men- 

 tioned in this memoir : the pale brown represents the new red sandstone and con- 

 glomerate, bituminous schist, coal measures, old red sandstone and conglomerate ; 

 and the dark brown the lias, the oolitic series, and its subordinate coal bed:^, 

 as described in the present volume : p. 125. 



Plate XIV. 

 Fig. 1. Section from the north coast of Caithness : p. 132. 



* The two fossil fish figured in this Plate were found during the passage of the paper through 

 the press, and only one of the specimens is alluded to above (p. 118). No generic and specific 

 names are given to these imperfect specimens : but it may be observed that they do not belong to 

 the genus Chajtodon, or to the genus Stromateus. It may be proper to state, that a fossil fish of 

 the genus Palseothrissum occurs abundantly in the coal formation of Saarbruck ; an additional 

 fact to show the near connexion between the fossils of the magnesian limestone and those of the 

 inferior formations. (See p. 99.) 



