PLATE XIX. 



(The cost of this plate has been defrayed by the Carnegie Trust for the Universities 



of Scotland.) 



Fig. 



1. Gonatodus pitnclatus (Agassiz) ; natural size. From the Calciferous Sandstone Series, 



Wardie. In the Collection of the Author. 



2. Maxillary bone of the same species ; magnified two diameters. This is one of the 



types of Walker's Amblypterus anconoachmodus. From Pitcorthie, near 

 Anstrnther. In the Royal Scottish Museum, Edinburgh. 



3. Uentary bone, magnified two diameters. This is also one of the types of Walker's 



Amblypterus anconoachmodus. From Pitcorthie, near Anstruther. In the Royal 

 Scottish Museum. 



4. A single mandibular tooth seen antero-posteriorly and magnified eight diameters. 



5. Flank scale of an ornate character from a Pitcorthy specimen ; magnified four 



diameters. Royal Scottish Museum. 

 (5. Under surface of a similar scale ; magnified four diameters. 

 7. Flank scale of a less ornate character; magnified five diameters. 



