250 C. W. Andreics — ^pyornis from Madagascar. 



the head ; anteriorly it forms a very large projection. The upper 

 part of the shaft is rounded, but farther down it becomes somewhat 

 flattened from before backward. The condyles project far forward, 

 and the outer extends considerably below the inner. There is 

 a deep popliteal fossa into which pneumatic foramina open ; there 

 is also, in most cases, a pneumatic opening at the upper end of 

 the bone on the posterior surface. In the tibio-tarsus there is 

 a large cnemial crest, which rises considerably above the proximal 

 articular surface. The shaft is compressed from before backward, 

 and its anterior face is much flattened, particularly in its lower half ; 

 there is no bony extensor bridge. The distal articulation is very 

 broad, and the two condyles are not separated by a deep inter- 

 condylar groove, but form a continuous cylindrical surface. 



In the metatarsus the proximal articular surface is very wide 

 from side to side, and narrow from before backward : there is no 

 intercondylar tubercle. The hypotarsus is simple, and forms a very 

 high ridge on the posterior surface of the upper portion of the bone. 

 The anterior face is deeply concave above, but narrows and becomes 

 nearly flat anteriorly a little above the distal articulation. The 

 trochlese are very large : the inner arises at a somewhat lower level 

 than the outer, and extends farther downward. There is no 

 perforation for the tendon of the adductor of the outer digit. 



The toes of the present specimen seem to be relatively rather too 

 small, although some of the largest phalanges were used for their 

 reconstruction. The phalanges are compressed from above down- 

 ward in the middle and outer toes, while in the inner they are 

 more cylindrical. The ungual phalanges are broad, slightly curved, 

 bluntly pointed claws. In the collection no bones that can be 

 regarded as having belonged to a hind toe occur, but the markings on 

 the hinder surface of the metatarsus seem to show that at least 

 a rudimentary hallux must have been present. 



Some approximate measurements of the skeleton as mounted are 

 given below : — 



cm. 



Height to top of crest of ilium ... ... ... ... 116 



Height to middle of acetabulum ... ... ... 96 



Height to top of skull ... ... ... ... ... 158 



Length of femur 31 



Width of lower end of femur ... ... ... ... 12 



Length of tibio-tarsus ... ... ... ... 56'5 



Width of lower end of tibio-tarsus 10-5 



Length of metatarsus ... ... ... ... ... 29 



Width of upper end of metatarsus ... ... ... 11 



Width of lower end of metatarsus 10-5 



Width of middle trochlea 4-5 



Length of ilia ... ... ... ... ... ... 56 



Width of pelvis at anti -trochanter ... ... ... 25 



Least preacetabular width 17"5 



Length of free portion of ischium ... 28'5 



Distance between distal ends of ischia 30 



Distance between distal ends of pubes ... ... ... 33 



Height of first pelvic vertebra ... ... ... ... 17 



