1903. | OSTEOLOGY OF THE CUCULIFORMES. 277 
appears to have been thrust forward by a considerable increase in 
the length of the posterior sternal ribs. As a consequence, the 
shaft of the coracoid and the long axis of the sternum form nearly 
a right angle with the vertebral column, and the shaft of the 
scapula lies parallel with the vertebral axis, instead of forming an 
oblique angle therewith. This forward movement of the sternum, 
furthermore, has brought the acrocoracoid upwards to the level 
of the neural crests of the vertebree, whilst the distance between 
the acetabulum and the free edge of the metasternum has been 
enormously increased. Jn fact, the thorax of this bird approaches 
very closely, in the relative position of the sternum, that of the 
“* Ratitee.” 
Text-fig. 43. Text-fig. 44. 
Text-fig. 43.—Left side view of sternum and shoulder-girdle of Cuculus canorus, to 
show the great size of the carina sterni and the form of the posterior border 
of the sternum. 
Text-fig. 44.—Left side view of sternum and shoulder-girdle of Coua reynaudi, to 
show the degenerate carina sterni, which is actually more reduced than the 
figure indicates. Note also the long hypocleideum and the doubly notched 
corpus sterni. 
Shortening of the sternum is most marked in Piaya, Zanclo- 
stomus, and Taccocoua. 
The sternum of the Musophagi is relatively longer and more 
Coraciiform than that of the Cuculi, butisatthesametime thoroughly 
Cuculine in character. In both Zwracus and Schizorhis, the only 
genera represented in the National Collection, the hinder border 
of the sternum is doubly notched, and the notches are of consider- 
able extent, the outermost being the deepest. The posterior 
lateral process is slender, and directed straight backwards. The 
intermediate process lies midway between the posterior lateral 
process and the metasternum. The outermost notch is about 
twice the depth of the inner. 
The corpus sterni of Turacus is relatively much shorter antero- 
