''^'o'"'] PROCEEDINGS OF THE NATIONAL MUSEUM 129 



between P. vigua aud P. mexicanus are at most subspecific, aud this 

 seems to be borue out by the osteology of the two birds. 



The frontal region of P. mexicanus is wider than that of P. vigua in 

 the specimens at hand, but this is very likelj' a case of individual var- 

 iation, as cormorants are slightly variable in this as in other respects. 



Urile magellauica (Gmel.) • 



Elizabeth Island, Straits of Magellan, two specimens, January 20. 

 (18428,18 480.) 



The skeleton of this bird shows it to be nearly related to Urile urile, 

 although compared with that bird the skull is i)roportionately larger 

 and the pterygoids much shorter, wider, and more S-shaped ; the ridge 

 of culinen is also wider. 



The ilio-ischiatic foramen is narrower in U. mageUanica than in U. 

 urile; otherwise the pehis of the two species are much alike. 



Urile albiventer (Less.). 



Elizabeth Island, Straits of Magellan, two specimens, January 20. 

 (18427, 18481.) 



This bird is a near relative of (J. carunculata (Gm.), and the crania 

 of the two species are upon their superior aspect indistinguishable. 



On the ventral aspect the pterygoids of U. carunculata are seen to be 

 much more slender, straight, and narrow than those of albiventer, as 

 well as slightly longer. 



The pterygoid bones appear to offer some very good specific charac- 

 ters, and in the species examined, with the exception of P. vigua, cor- 

 morants from the southern hemisphere have these bones shorter than 

 do those from the north. 



U. albiventer and U. carunculata may be immediately distinguished 

 amid all other species examined by their slender, strongly ridged 

 beaks, aud large globose calvaria. 



The occipital style of these two birds is short, and less definitely 

 grooved than in other cormorants. 



Family PHCENICOPTERID^. 

 Phoenicopterus ruber (Linx.). 

 Charles Island, Galapagos Group, April 8. (18494, 18495.) 

 Family ANATID.E. 

 Cloephaga magellanica (Gmel.). 

 Port Otway, Patagonia, February 10. (18552.) 

 Cloephaga antarctica (Gmel.). 

 Port Otway, Patagonia, February 10. (18554.) 

 Proc. N. M. 90 9 



