AUTHOR S ABSTRACT OF THIS PAPER ISSUED BY 

 THE BIBLIOGRAPHIC SERVICE, DECEMBER 2 



NOTES ON THE OSTEOLOGY OF THE YOUNG OF THE 



HOATZIN (OPISTHOCOMUS CRISTATUS) AND 



OTHER POINTS ON ITS MORPHOLOGY 



R. W. SHUFELDT 



EIGHT FIGURES (FOUR PLATES) 



In the winter of 1914-15, I received from Mr. Robert Cush- 

 man Murphy several specimens of the subadult and young of 

 Opisthocomus cristatus. My impression is they were collected 

 in Guiana by Mr. George Cherrie though I may be mistaken in 

 regard to this. Dr. James E. Benedict, of the United States 

 National Museum, had Mr. Scollick, the skillful preparateur of 

 that institution, prepare the skeletons of two of these speci- 

 mens for my use in descriptive work (figs. 1 and 2). Upon this 

 account I presented the entire lot to the National Museum in 

 February, 1914. (Mus. No. 223903.) 



There is considerable literature on the hoatzin, which dates 

 back to the writmgs of Miiller and of Gmelin, the latter passing 

 the bird into the genus Phasianus of Linnaeus, while Buffon 

 considered it to be a curassow. Illiger created the genus Opis- 

 thocomus for it in 1811, and, twenty-six years later, L'Herminier 

 gave a fairly good account of its anatomy. 



Figure 1 is from a subadult specimen, taken in the pin-feather, 

 just before it is able to fly; the bird w^as probably double the age 

 of the chick whose skeleton is shown in figure 2. In the latter, 

 almost the entire skeleton is still in cartilage, although minute 

 ossific centers can be detected in the basi-occipital of the skull, 

 but not distinctly in any other bone. However, even at this 

 age the main osteological characters of the species are quite 

 apparent. 



Superficially, the skull, as a whole, reminds one of the skull of 

 the chick of Gallus ; though upon direct comparison, character for 

 character, the resemblance is soon dispelled. As in the adult, 



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