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



where we find Geococcyx, Crotophaga and Guira all associated in 

 another group b. 



To this last arrangement I very much demur, and doubt that the 

 retention of Geococcyx and Crotaphaga in the same subfamily at all 

 expresses the natural affinities of these forms within the family. It 

 will be seen later that they are very distinct types of Cuckoos, in so 

 far as they are osteologically organized. As I have already stated 

 elsewhere, I believe the Crotophagince constitutes a distinct sub- 

 family, and the summation of the entire morphology and a knowl- 

 edge of their especial habits will go far towards supporting this 

 arrangement. 



Osteology of Geococcyx. 



Of the Skull. — In Geococcyx we find the osseous superior mandi- 

 ble with a gently curved and rounded culmen, the curve increasing 

 very modestly as it approaches the apex. This part of the skull has 

 a broad base, being both deep and wide in the rhinal region, while 

 on all aspects it tapers gradually to the slightly decurved tip. Its 

 buccal surface is flat, with cultrate edges somewhat raised above the 

 general plane behind. Posteriorly, this face' is encroached upon by 

 the palatines and maxillo-palatines. Turning to the lateral surfaces 

 of this mandible (PI. I, Fig. i), we find them for the most part to 

 be slightly convex throughout their extent ; the only exception to 

 this being seen in the depressions which are found, one over each 

 of the scale-like projections that close the hinder two-thirds of either 

 nostril. 



These last-mentioned openings are of a subelliptical outline, 

 placed longitudinally nearer to the edge of the beak than its culmen 

 and just posterior to its middle. They do not directly communi- 

 cate with each other, but are external apertures, in this bird, of 

 osseous tubes, one on either side, which are produced backwards 

 nearly to the rhinal chamber, being encased in the loose, osseous, 

 spongy mass that almost fills the otherwise hollow superior mandible 

 of Geococcyx. 



In the skull freshly prepared, and before it dries, the cranio-facial 

 hinge enjoys considerable mobility, and its position is clearly indi- 

 cated by a transverse track. Mesially, this region is depressed, and 

 may show the last sutural traces of the nasal processes of the pre- 

 maxillary therein. Each nasal bone has been so completely met 

 by the various surrounding elements that, save its hinder margin, 



