1894.] 



IN THE BRITISH MUSEUM. 



109 



JE„ sp. 



Length 



Width of proximal end 



Width of distal end 



Width of shaft at narrowest 

 point 



Circumference of shaft at nar- 

 rowest point 



Width of middle trochlea 



cm. 

 31-6 



11-5 



11-9 



5-4 



13-6 

 4-7 



M. maxim/us. 



cm. 

 37-0 (?) 



14-5 



8-0 (?) 



20-0 

 5-2 



M. Mldebrandti. 



cm. 



27-5 



9-5 

 100 



4-5 



11-0 

 43 



At the proximal end the inner glenoidal cavity is the deeper of 

 the two ; it is oval in outline, the long axis being antero-posterior, 

 and its front and hind borders are produced upwards into blunt 

 points, of which the hinder is much the higher. The outer glenoidal 

 cavity is shallow, and slopes down at its antero-external edge, 

 where it has no well-defined border. These two cavities are 

 separated by a surface, plane behind and slightly concave from 

 side to side in front ; there is no distinct median groove such as 

 is said to occur in 2E. Mldebrandti. There is no trace of an inter- 

 condylar process. As in the other members of the genus hitherto 

 described, the anterior surface of the shaft is deeply depressed in 

 the middle line at the upper end, the depression dying away 

 downwards, till a little above the trochlea the bone is slightly 

 convex from side to side. At the deepest part of the depression, 

 about 5 cm. from the proximal end of the bone, the foramina interossea 

 open. They are about 1 cm. apart and at the same level, thus 

 differing from M. hildebrandti, where the outer is rather above the 

 inner. Immediately below them there is a large rugose tuberosity 

 for the insertion of the tibialis anticus. In the upper part of the 

 outer surface is a rather broad groove passing obliquely from the 

 anterior face to the posterior, where it dies away. The talon 

 consists mainly of a broad blunt riclge, continuous with the upper 

 end of the middle metatarsal and lying slightly to the outer side 

 of the middle line. Internal to this is a broad, short, and very 

 shallow groove, bounded internally by a low blunt tubercle lying 

 immediately above the inner interosseous foramen. 



The lower part of the posterior surface closely resembles in 

 general appearance tha,t of AZ. Mldebrandti, but is remarkable 

 from the fact that it shows a distinct trace of the presence of a 

 hind toe. Although several authors state that JSpyornis possessed 

 four toes, I am not aware that any trace of the presence of a 

 hallux is to be found in any specimen described till now. On the 

 postero-internal surface, about 9 cm. above the distal end of the 

 inner trochlea, is a bony projection, measuring 3 cm. from above 

 down, and 1 cm. from side to side ; it rises to a height of about 



