EXPLANATION OF THE PLATES. 



Fii^s. 2. 5. Sections from the Old of Caithness and the Maiden Paps to the upper red 



sandstone of Dunnet Head : pp. 135. 141. 

 Fio: 3. Section from Ben Wyvis to tlie North Sutor of Cromarty : pp. 145. 148. 149. 

 Fig. 4. Section from the hiils of Spey through the extreme point of Tarbet Ness to 



the granitic hills of Sutherland : p. 150^ &c. 

 Fig. 5. Section through the Maiden Paps and Scarabins : pp. 138. 139. 



Plate XV. 



Figs. 1. 2. 3. Dipterus macropygopterus. Of these fig. 1. is the most perfect specimen, 



showin"- a pointed anal fin prolonged nearly as far as the inferior lobe of the 



caudal fin : p. 143. 

 Fio: 2. This specimen is represented with the belly upwards, and the double fin of 



the back downwards. (See the bend of the lateral line.) 

 Fig. 3. In this the caudal fin is less clearly seen tlian in No. 1., although the generic 



and specific characters are not wanting. 

 Fio-. 4, The genus Dipterus restored in all its parts. (A sketch by the hand of Baron 



Cuvier.) : p. 142. 



Plate XVI. 



Fio-s. 1.& 3. Dipterus Valenciennesii : p. 143. 



Fio: 2. Dipterus maci-olepidotus (young) : p. 143. 



Fio-s. 4. & 5. Fragments of Dipterus macrolepidotus : p. 143. 



Fig. C. Fragment of Trionyx : p. 144. 



Fig. 7. Operculum of Dipterus. 



Plate XVII. 

 Figs, 1. 2. 3. Dipterus brachypygopterus : p. 143. 



PLATES XVIII. XIX. XX. 



Illustrate Mr. De la Beche's paper on Tor and Babbacombe Bays. 



Plate XVIII. 



Contains a Geological Map of the coasts of Tor and Babbacombe Bays, and Sections, 

 pp. 162. 163. 166. 169. 



Plate XIX. 



Examples of contorted carboniferous limestone near Torquay, showing that the 

 curvature of the strata has been effected in all directions : p. 165. 



