46 



MR. W. P. PYCRAFT ON THE 



[May 2, 



should rather be described as blade-shaped, the dorsal edge of the 

 blade beuig much thickened ; in other words, the ventrally placed 

 keel of the triangle seen in Corydon has in this genus extended 

 downwards. The median line of the dorsal surface of the corpus 

 sterni is deeply grooved, and pierced anteriorly by a large 

 pneumatic foramen. In Cymhirhynchus^ and to a less extent in 

 Ccdyptoonena, the groove is laced across by narrow, irregular bars 

 of bone. 



The carina is deep, and has the free (ventral) edge produced 

 forwards. The anterior (vertical) border bears a hollow groove for 

 the reception of the hypocleideum. 



The coracoid gi-ooves look directly forwards, and do not meet in 

 the middle line. The doi-sal lips ai'e prominent and thickened ; 

 the ventral lips are well-defined, but have knife-like edges con- 

 tinued inwards on to the sjnna externa. 



Text-fio-. 13. 



,.y.7./. 



Sternum of Cal yptoniena , showing the simple (unbifurcated) spina externa, s.e. 

 a J. p., anterior lateral process; c, carina; pJ.p., posterior lateral process. 



The coracoids are long ; as long as, or longer than, the corpus 

 sterni. The procoracoid process, though reduced, is still moderately 

 large, and forms a narrow flange of bone, arising beyond the 

 middle of the coracoid shaft and having its free edge directed 

 downwards. Oephalad it articulates with the scapula, and with 

 the clavicle forms the foramen triosseum. The procoracoid of the 

 Emylsemidre is larger than in the Cotingidie. In the Picida; the 

 procoracoid appears to be wanting, and in the higher Passei'es it 

 is redviced to the merest vestige, e. g. Corvus. The breadth of the 

 base of the coracoid is increased by narrow phalanges of bone, one 

 on either side extending forwards, for about one-fourth the length 

 of the shaft. On the dorsal aspect of the shaft a jDrominent 

 tongvie of bone is sent up to abut against the dorsal lip of the 

 coracoid groove. This at least obtains in Caly2)tomena ; in 

 Corydon and Cymhwliynclius it is less marked. 



The scapida is long, narrow, and scimitar- shaped. The furcula 



