32 SHUFELDT — OSTEOLOGY OF THE CUCKOOS. [Jan. 4, 



skull of the Common Puffin (Fratercula), but upon careful scrutiny 

 we at once see that Crotophaga possesses a true cuculine skull, and 

 one that, for at least the posterior moiety of the basal aspect of its 

 cranium, reminds us not a little of Huxley's figure of Cuculus 

 ca?wrus (P. Z. S., 1867, p. 444, Fig. 26). Among our Cuckoos, 

 however, Caccyzus is the bird that appears to have a skull most like 

 Cuculus, and Crotophaga upon the lateral view of its skull reminds 

 us of neither of those species. 



Regarding the skull of this Ani upon its upper aspect, we are 

 enabled to see how the subcompressed, lofty superior osseous man- 

 dible mounds up mesially just in front of the very distinct cranio- 

 facial line. The culmen is sharp and arches over handsomely to 

 the tip of the decurved apex of the beak. The small subcircular 

 nostrils can also be partially seen upon this view and the minute 

 foramen that perforates either nasal bone. The large lacrymals 

 have much the form they have in Geococcyx and articulate with the 

 surrounding bones in precisely the same manner. Longitudinally, 

 in the middle line, between the orbits, the frontal region exhibits a 

 moderately-raised, rounded eminence, extending backward upon 

 this aspect as far as the vault of the brain-case ; and this inter- 

 orbital space is quite broad in Crotophaga — proportionately much 

 more so than it is in Geococcyx. 



This breadth is likewise enjoyed by the smooth, rounded super- 

 ficies of the cranial vault. 



Laterally this skull presents a well-marked temporal (crotaphyte) 

 fossa ; a small post-frontral process directed downward, and a 

 much larger arched squamosal one directed forward and only 

 slightly downward. 



The quadrato-jugal bar is straight and slender between quadrate 

 and lacrymal, while the small sesamoid at its posterior end seems to 

 be in a ligament passing from it to the os quadratum. 



The capacious orbits are only separated from each other by a 

 thin, incomplete septum, and the foramina in the anterior wall of 

 the brain-case are large and may merge to some extent. 



Os quadratum is large, with a good-sized orbital process. Its 

 various projections are thin and compressed, while a deep notch 

 separates its two mandibular facets. Pars plana is also of good 

 size, fusing with the frontal above, where it is pierced internally by 

 a single foramen (two in Geococcyx) ; its infero-external angle 

 being somewhat drawn out into a stumpy apophysis. This osseous 



