NEW FOSSIL BIRD. 



521 



about 1 cm. from their hinder extremity ; it is not possible to tell 

 whether there was an accessory posterior coracoid groove as in 

 the Petrels generally, that region of the sternum having been lost. 

 Beneath and between the anterior ends of the coracoid grooves is a 

 strongly developed spina exte7'na {sp. ext.), the anterior escutcheon- 

 shaped face of which was nearly vertical with regard to the long 

 axis of the sternum ; from its ventral angle a strong intermuscular 

 I'idge is continued down the anterior border of the carina, dividing 

 it into two lateral surfaces and terminating at the upper border of 

 the facet for articulation with the furculum. The carina itself is 



Text-figure 2. 



Sternum of G-iganlomis eaglesomei, from front, h natural size. 

 e.g., coracoid groove; f., facet for furcula; sp.ext., i=pina externa. 



deep and is prolonged forwards and downwards ; posteriorly it 

 seems to have narrowed with exceptional rapidity, so that it may 

 have been confined to the anterior portion of the body of the 

 sternum, but, owing to the incompleteness of the specimen, its 

 precise form cannot be determined. The anterior border is broad 

 above and concave from side to side on either side of the median 

 ridge above referred to ; externally it is separated by sharp angles 

 from the lateral surfaces. Lower down the anteiior border 

 narrows and becomes convex from side to side. The antei-ior 

 angle of the carina, which projected rather strongly forwards, is 

 truncated b}^ an extraordinarily large surface for union with the 



