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



Notes on the Skeleton of a Nestling of Coccyzus ameri- 



.canus. 



Allusion has already been made in a former paragraph of this 

 memoir to the material here to be considered. The skeleton I have 



aperture is much as we find it in Geococcyx. The frontal region is narrow, 

 concaved, and the cranial vault agrees in form with that region in Coccyzus. 



The temporal or crotaphyte fossae, though well marked, are confined to the 

 lateral aspect of the skull. Postfrontal and squamosal processes agree better 

 with what we found in Crotophaga sulcirostris, while the quadrate agrees in 

 form with that bone in the average cuculine types. The central portion of the 

 interorbital septum is very deficient in bone, as in the Ground Cuckoos. A pars 

 plana is ample, quadrilateral in outline and exhibits a single nervous foramen 

 above it. The lacrymal practically agrees with that bone as it is seen in Geo- 

 coccyx, as does the quadrato-jugal rod. Turning to the base of the cranium, we 

 find a pterygoid to agree with the corresponding element in Coccyzus, with its 

 superior crest still better marked. The palatines, although cuculine in their 

 general features, are peculiar, for their prepalatine portions are markedly 

 narrow, their widest parts being at the middle of the postpalatines, and finally a 

 distinct, spiculiform process of no great length juts out from either postero- 

 external angle. 



A rudimentary spine-like vomer may be present. Posteriorly, the backward- 

 extending bulbous ends of the maxillo-palatines are well separated in the median 

 line, and it is only anteriorly that desmognathism is shown by the fusion of these 

 processes with the mass of spongy bone tissue occupying the forepart of the 

 rhinal chambers. 



This last seems to be deposited about a true osseous septum narium. Either 

 nasal is perforated by a minute foramen, to which I have invited attention in 

 other Cuckoos and the Kingfishers : internally one of the elements develops an 

 osseous spine that is sent downward and inward toward the maxillo-palatine of 

 the same side. The maxillaries are typically cuculine. 



The mandible is V-shaped, decurved, with short symphysis and small ramal 

 vacuity. 



Diplopterus ncevius has eighteen free vertebras between skull and pelvis, with 

 the ribs arranged just as we find them in Geococcyx ; it differs, however, in 

 having six free vertebra? in the skeleton of the tail, with a pygostyle that differs 

 somewhat in form with that bone in both Coccyzus and the Centropodince, in 

 that its postero-superior angle is not drawn upward so as to be rather more 

 prominent than its antero-superior angle — which feature is best seen in Coccyzus. 

 The bones of the shoulder girdle are characteristically cuculine, with the scapulse 

 long and very narrow, as in Crotophaga sulcirostris. 



In the form of its sternum it agrees with Coccyzus americanus, but shows a 

 few distinctive features in its pelvis, for in Diplopterus the ilia anteriorly are 

 more decidedly separated from the sacral crista, and the postpubic elements are 

 well drawn out behind as inturned slender spines, as we see them in many Pas- 

 seres. Otherwise the pelvis of this interesting Cuckoo does not differ so very 

 much from lhat bone of the skeleton as it occurs in our genus Coccyzus. 



