160 ON REMAINS Oi' A GIGANTIC BIED PEOM LOWEK EOCENE BEDS. 



DESCRIPTION OF THE PLATES. 



Index to letters. 



ax. Anterior crest of femur. 

 a.h. Articular head of femur. 

 fih. Lower attachment of fibula. 

 fib.art. Articulation for fibula. 

 i.a.r. Inner articular rugosity. 



i.e. Inner condyle. 

 ic.d. Intercondylar depression. 

 i.t. Inner epicondylar tuberosity. 

 l.a. Lower attachment of oblique 



ligamentous bridge. 

 o.G. Outer condyle. 



o.t. Outer epicondylar tuberosity. 

 o.tt. Outer tuberosity of femur. 

 p.t. Posterior tuberosity of femur. 

 pt.s. Posterior trochlear surface. 

 t.a. Foramen for tibial artery. 

 t.c. Canal for tendon passing under 



bridge. 

 t.g. Groove for peroneus tendon. 

 tr. Trochanter of femur. 

 s.art. Superior articular surface of femur. 

 s.t.b. Ossified supratendinal bridge. 



PLATE XXVIII. 



Fig. 1. Oasfornis klaasseni, right tibio-tarsus, outer surface partly restored. 



Fig. 2. Ditto, same specimen, front view. 



Fig. 3. Ditto, same specimen, inner .surface. 



Fig. 4. Ditto, parts of a tibia of a very young bird, front view. 



Fig. 5. Common Goose, right tibio-tarsus, front view. 



Fig. 6. Herring-Gull, right tibio-tarsus, front view. 



Figs. I to 4 half natural size ; figs. 5 and 6 natural size. 



PLATE XXIX. 



Gastornis klaasseni. 

 Fig. 7. Distal end of left tibio-tarsus, front view. The form of the bridge and its lower 



aperture are not correctly shown in this figure. 

 Fig. 7 a. Same specimen, view of upper broken surface. 

 Fig. 8. Same specimen, inner surface. 

 Fig. 9. Same specimen, outer surface. 

 Fig. 10. Same specimen, back view. 

 Fig. 11. Same specimen, seen from below. 



Fig. 12. Part of shaft of a tibio-tarsus from just above the supratendinal bridge. 

 Fig. 12 a. Transverse section of upper end of same specimen. 

 Fig. 1.3. Left femur, proximal portion, front view. 

 Fig. 13 «. Transverse section of lower end of same. 

 Fig. 14. Another portion of same femur, from near condyles. 

 Fig. 14 a!. Transverse section of upper end of same. 

 Fig. 15. Same specimen as figure ]3, seen from above. 



Figs. 7-15 half natural size. 



