300 Annai.s of the Carnkgie Museum. 



and hang down as very conspicuous features of the lateral aspect of 

 the skull. In most particulars they are like the lacrymals as found 

 among many Geese and Swans, and entirely different from those bones 

 in such an Ibis as Pkgadis, or its near allies. In all true Anseres, 

 however, the lacrymals always anchylose with the cranium in front of 

 the orbit. 



Y^xthcr zygoma in Phocnicoptenis is a straight, stout bar of bone, that is 

 more or less transversely compressed. At its proximal end it develops 

 the usual little inturned process for articulation with the quadrate, 

 while along its shaft all traces of the sutures indicating the original 

 bones that enter into its composition are absent in the adult. Beyond 

 the lacrymal it gradually becomes very much broader, and twists upon 

 itself so that the anterior part of the inaxillary portion lies quite in the 

 horizontal plane. This extremity, fusing completely with the sur- 

 rounding bones, passes in between the maxillo-palatine and the pala- 

 tine, being above the latter. In the Swans, Geese and Ducks the 

 zygoma is much slenderer ; shows very little enlargement ^nd no 

 twisting anteriorly, and in them passes in between the pre-maxillary 

 and palatine, being below the latter. This is a radical as well as a very 

 interesting difference. 



In Plegadis the maxillary end of the zygoma lies above the anterior 

 end of the palatine of the same side. A large vacuity exists in the 

 interorbital septum of the Flamingo, and in either orbit another ex- 

 tensive foraminal opening occurs above this in the anterior wall at the 

 brain-case. Both in Ibises and anserine birds the interorbital sep- 

 tum is more or less entire, though the foraminal openings into the 

 cephalic-casket may be of the same size, especially in the former 

 group. In Plegadis the pars plana meets the lacrymal of the same 

 side, but in neither the Flamingoes nor in the true anseres do these 

 ethmoidal wings of the mesethmoid develop in bone. 



In Phcenicoptenis r///^<?;- both the post -frontal and the squamosal proc- 

 esses are very much aborted, and the temporal valley between, though 

 deep, is of limited extent. These processes are likewise singularly 

 small in Plegadis. A very different state of affairs exists in the Anseres 

 in this particular. In them the squamosal process maybe quite absent 

 or, if present, so small as not to attract attention. On the other hand, 

 these birds usually possess a post-frontal process of uncommon lengtft. 

 Its tendency is to extend forward and meet the backward extending 

 lacrymal bone. This is actually accomplished in the duck known as 



