148 ODONTORNITHES. 



The manubrium closely resembles that of Iclitliyornis dispar. The cora- 

 coid grooves overlap widely on the median line, the left being above the 

 right, as in Iclrtlujornis dispar. The costal processes and the posterior 

 outline of the specimen are not preserved. 



In the genus Apatornis, the sternum was keeled, as in Iclithyomis, 

 although the precise depth of the keel cannot be determined. The manu- 

 brium was narrower than in IcMJiyornis, and symmetrical, and ended in a 

 blunt point. The coracoid grooves scarcely more than meet on the 

 median line, and the left is but little depressed below the right, the asym- 

 metry being only about as great as in Graculus dilophns, Gray. The costal 

 process is triangular, and the costal border presents six articular faces for 

 sternal ribs. The first of these is comparatively small and indistinct, and 

 is well in advance of the five succeeding ones. The latter are separated 

 by nearly equal intervals, each about two-thirds as long as the first. The 

 posterior outline of the sternum is much broken, but appears to have been 

 deeply emarginate. 



The following measurements are taken from the specimens mentioned 

 above : 



Measurements of Sternum. (Iclithyomis dispar, No. 1450.) 



Transverse diameter, near anterior end, ^ 32.5 mm 



Depth of keel, as preserved, 10. 



Measurements of Sternum. (Ichthyornis victor, No. 14(51.) 



Length of keel, at base, 34. mm 



Maximum length of keel, 45. 



Depth in front, 13.5 



Measurements of Sternum. (Apatornis celer, No. 1734.) 



Greatest transverse diameter, 33. mm 



Least transverse diameter, 28. 



