SHUFELDT : OSTEOLOGY OF THE STEGANOPODES 217 



led to believe, if it be not actually the case, that the strong-hooked beak in the 

 skull of Fregata is a diomedean character rather than a pelicanine one. Apart 

 from the free ends of the furcula coalescing with the coracoids, there are characters 

 in the sternum and shoulder-girdle of Fregata which also recall the forms of the 

 corresponding bones in the Albatrosses, but beyond this there appears to be nothing 

 else in the skeleton of the Man-o'-War Bird at all reminding us of those birds. 



As this relationship exists between Fregata and Diomedea, remote as it may be, 

 it nevertheless, taken in connection with what has been pointed out above in regard 

 to Phaethon and Puffinus, ou^ht to lead us to believe that the Steganopodes are more 

 closely affined with the Tubinares than they are with the Longipennes. 



There are those who claim to see a kinship existing between the Accipitres and 

 the Fregatoidea, but there are surely no indications of it in so far as the osteology 

 of any of the representatives of the two suborders in question are concerned. 



Addenda. 



Since writing the above account of the osteology of the Steganopodes, I have per- 

 sonally reexamined some of the material in the United States National Museum, 

 and, thanks to the marked kindness of Mr. F. A. Lucas, the able Curator of the De- 

 partment of Osteology of that institution, I have been permitted fully to examine 

 and compare the entire collection there, constituting as it does the finest assortment 

 of material illustrating the osteology of the Steganopodes in existence. A number of 

 the specimens drawn from this material are now figured for the first time in the 

 plates to the present memoir. 



To what I have already set forth in the body of the paper, there is nothing I find 

 in particular to add to the osteology of the Phaethontidce or the Sulidse. Among the 

 Plotidse (the Anhingidse of the A. O. U. "Check-List ") I examined a skeleton of Plotus 

 levaillanti, and it presents all the usual characteristics of the skeleton in that family 

 of birds. A dorsal view of its pelvis is given in Plate!., Fig. 1, which will assist in 

 illustrating what I have said in the body of the memoir in regard to the skeleton 

 of P. anliinga. I have never had the opportunity to examine the skeletons of the 

 two other known species of this family. (Sharpens "Hand-List of Birds," p. 236.) 



The collection of Cormorant skeletons {Phalacrocoracidx) in the U. S. National 

 Museum is, as I have said above, the finest in the world at the present writing, 

 nearly every known species being represented. It is Mr. Lucas' intention, some- 

 time in the future, I understand, to monograph this group, and it will be a very 

 valuable contribution to the subject. Their skulls present some very interesting 

 variations, and the majority of these are well shown in the figures of the Plates 



