SHOULDER-GIRDLE OF ICHTHYORNIS. 143 



Measurements of Scapula. {Ichthyornis dispar, No. 171S.) 



Greatest diameter, across humeral articulation, --. 7.5 mm 



Least diameter, through humeral articulation, 2.8 



Length of acromial process, from base, 0.6 



Measurements of Scapula. (Ichthyornis victor, No. 1452.) 



Greatest diameter, across humeral articulation, 8. mm 



Least diameter, through humeral articulation, - 3. 



Length of acromial process, from. base, - — 0.3 



The various bones in the scapular arch of Ichthyornis are shown in 

 position in the fig-ure below. 



Pig. 31. 



Figcee 31. — Scapular arch of Ichthyornis victor, Marsh; twice natural size. s. scapula; c. coracoid; cl. clavicle , 

 st. sternum; k. keel of sternum; sr. costal border ; g glenoid fossa. 



