•±2 SHUFELDT — OSTEOLOGY OP THE CUCKOOS. [Jan. 4, 



slender. Pars plana large. Interorbital septum thin, large central 

 perforation. 



6. Lacrymal large, its descending part lamelliform, broad. 



7. Basipterygoid processes completely aborted. Pterygoids 

 straight, moderately long, sharp on superior border. 



8. Vomer rudimentary: Palatines, plate-like, comparatively 

 broad and placed horizontally, with their postero-external angles 

 completely rounded off. Maxillo-palatines large, spongy, in con- 

 tact in median line, and with several of the surrounding bones, but 

 not with the vomer. 



9. Mandible V-shaped, sides rather deep, ramal vacuity small ; 

 angular processes stumpy, with the inturned ones long. Mandibu- 

 lar symphysis less than a third the length of the jaw. 



10. Elements of hyoidean arches slender; basibranchials short, 

 separate bones ; cerato-hyals very small, not in contact. 



11. Eighteen free vertebrae between skull and pelvis; cervical 

 ribs on the twelfth, thirteenth and fourteenth. Four pairs of dorsal 

 ribs, of which the three anterior pairs connect with the sternum. 

 One pair of very short pelvic ribs, directed backward. Pelvis 

 peculiar; anterior ends of ilia dilated, and their inner tips meet the 

 "sacral crista:" posterior to this they are contracted and are not 

 in contact with it. Small prepubic process present, and the ilia, on 

 either side, curl outwardly over the ischiac foramen. Postpubic 

 bones project but very slightly behind. Five caudal vertebrae and 

 a pygostyle ; the three last ones of the former having large hypapo- 

 physes. 



12. Os furcula U-shaped, slender, with large hypocleidium, and 

 articulates with both scapula and coracoid above. Blade of scapula 

 long and narrow. Coracoid long with rather slender shaft. 



13. Sternum short, moderately wide, with one pair of rather 

 shallow xiphoidal notches. (These latter are barely noticeable in 

 Cam.) Costal processes conspicuous. Manubrium small. Carina 

 subample, with its border concaved in front, forming a prominent 

 carinal angle. Pneumatic. 



14. Humerus longer than either radius or ulna; radial crest 

 short ; shaft having the sigmoidal curve. This bone is pneumatic, 

 and the pneumatic fossa is very shallow and the foramen usually 

 single. Radius is straight and slender ; the ulna is bowed and 

 stout, and has down its shaft the row of papillae for the insertion of 

 the quill-butts of the secondary row of feathers. Carpal bones two. 



