1901.] SHUFELDT — OSTEOLOGY OF THE CUCKOOS. 39 



Some points of interest are to be seen in the trachea of Coccyzus, 

 for in this Cuckoo, the tracheal rings differ very markedly from 

 what we found to be the case in Geococcyx, in that some of them 

 are as fully and completely ossified as are any of the tracheal rings 

 among the Passer es. This is likewise the case in Centropus. The 

 pessulus also ossifies, as do the arytenoid bones and the thyroid 

 plate. 



As for the hyoidean apparatus it seems to agree with the skeleton 

 of it in all ordinary Cuckoos, and practically agrees with the corre- 

 sponding parts in Croiophaga} 



No especial nor detailed description is required for the pectoral 

 and pelvic limbs of Ccccyzus. The skeleton of these parts is cucu- 

 line in all particulars, differing but little from what has already 

 been described above for other United States Cuckoos. 



In the case of the pelvic limb, this genus of birds agrees with Croio- 

 phaga in that pro- and ecto-cnemial processes of the tibio-tarsus are 

 quite feebly produced ; while, on the other hand, the hypotarsus of 

 the tarso-metatarsus agrees with the corresponding apophysis as we 

 found it in Geococcyx in that it exhibits two vertical perforations 

 for the passage of tendons, instead of one, as we found to be the 

 case among the Anis. Coccyzus also has the fibula short and weak, 

 and the patella in this Cuckoo is comparatively very small. 2 



the os furcula; the amount of fusion engaged in between the sacral crista and 

 the internal margins of the ilia, and other points ; and this remark applies to a 

 number of other species and genera of the Tree Cuckoos; 



1 This statement must be taken only tentatively, for peisonally I rely upon 

 Beddard's description of the ossifications of the trachea in Croiophaga, and a 

 fuller examination of the trachea in Coccyzus may go to show that the parts are 

 more alike in Coccyzus and Geococcyx than in Coccyzus and Croiophaga. It 

 is a point that requires more extended examination. In fact all these structures 

 need a much fuller reseirch than they have as yet had bestowed upon them. 



2 Since the above account was written I came across some special cotes that I 

 had made and set aside five or six years ago upon the skeleton of Diplopterus 

 ncevius in the collection of the U. S. National Museum, and although these notes 

 duplicate one or two of the statements already made above, they are sufficiently 

 full in other particulars to warrant their being inserted here as a footnote to 

 render the account of the osteology of that species more complete. They run as 

 follows : 



In Diplopterus na:vius the superior osseous mandible is considerably shorter 

 than the remainder of the skull, measuring from the very distinct cranio-facial 

 line. 



Its culmen is rounded and the whole bill decurved, while the external narial 



