PLATE XX. 



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



of Scotland.) 



Fig. 



1. Elonichthys denticulatm, Traquair; flank scale, magnified ten diameters. From the 



Pendleside Series, near Holywell, Flintshire. Collection of J. T. Stobbs, Esq. 



2. Ventral scale from the same specimen ; same degree of enlargement. 



3. Elonichthys striatulus, Traquair ; from the Calciferous Sandstone Series, Glencartholm, 



Eskdale ; natural size. In the Royal Scottish Museum. One of the type specimens. 



4. Flank scale of the same species, magnified twelve diameters. From Gullane, East 



Lothian, in the Collection of the Geological Survey of Scotland. 



5. Scale nearer the tail ; same degree of enlargement. 



6. Drydenius Molyneuxi, Traquair ; from the Deep Mine Ironstone, Longton, Stafford- 



shire; natural size. In the British Museum. Type specimen. 



7. Flank scale, magnified. 



8. Impression of a portion of the mandible in an example of Drydenius Molyneuxi from 



the same horizon and locality ; magnified four diameters. In the Royal Scottish 

 Museum, Edinburgh. 



9. Gonatodus macrolepis, Traquair ; type specimen from the Gilmerton Ironstone, 



Venturefair Pit, Gilmerton, near Edinburgh. Collection of the Author. 



10. Flank scale enlarged four diameters. Same horizon and locality. 



11. Maxilla with teeth, enlarged two diameters, the post-orbital plate seen in impression. 



In the Royal Scottish Museum, from the same horizon and locality. 



12. Dentary bone of mandible with teeth, enlarged twice. In the Collection of the 



Author, from the same horizon and locality. 



13. Two mandibular teeth, magnified eight diameters. Gilmerton Ironstone. 



14. Tip of a maxillary tooth with a singularly mucronate point. 



