1857.] OWEN PLIOLOPHUS VULPICEPS. 71 



articular fossa for the astragalus on the tibia, and the three metatarsals 

 of the left hind-foot, all concur with the indications afforded by the 

 skull and teeth in the determination of the true position and affini- 

 ties of Pliolophus and, most probably therefore, of Hyracotherium 

 in the ungulate series. 



DESCRIPTION OF PLATES II., III.. & IV., 



Illustrative of the Pliolophus vulpiceps, Owen. 



Plate II. 



Fig. 1. Under view of the lower jaw and incisor teeth. 



2. Upper view of the cranium. 



3. Right-side view of the cranium and lower jaw, as attached together in the 



matrix. 



4. Left-side view of the cranium, with the lower jaw and teeth brought back 



to their proper place. 



Plate III. 



Fig. 1. Grinding surface of the molars and last premolar, upper jaw. 



2. The same, magnified 4 diameters. 



3. The first and second molar, upper jaw of an older individual. From the 



London clay, Valley of the Thames. 



4. Inside view of the molars and last two premolars, lower jaw. 



5. Grinding surface of the molars and last two premolars, lower jaw. 



6. The same, magnified 4 diameters. 



Plate IV. 



Fig. 1. Outer-side view of humerus. 



2. Front view of humerus. 



3. Proximal articular end of humerus. 



4. Inner-side view of proximal end of humerus. 



5. Front view of right femur. 



6. Upper articular end of right femur. 



7. Back view of right femur. 



8. Inner-side view of lower end of right femur. 



9. Lower articular end of femur. 



10. Back view of tibia. 



11. Upper articular end of tibia. 



12. Outer-side view of upper end of tibia. 



13. Part of lower articular surface of tibia. 



14. Portion of matrix, with the calcaneum and three metatarsals of the left 



hind-foot. 



[All the figures are of the natural size, except where otherwise expressed : the 

 letters and figures are explained in the text.] 



