2/8 NEW YORK STATE MUSEUM 



The projecting and rounded posteroexternal angle of the palatine 

 extends below this pterygoidal articulation. 



Generally the lower border of the rostrum is rounded; it is very 

 broadly so in the Brant, though it becomes quite flat in Clangula; 

 there it may be carried forward as a projecting process [fig. i8]. 



The anterior ethmoidal edge is generally sharp, and slopes for- 

 ward and upward to become a median crest on the under side of 

 that part of the bone which abuts against the frontal region for 

 its entire length. 



In Spatula the basitemporal region is quite broad, and marked 

 by a median and rounded ridge. This is carried out upon the 

 pointed lip of bone that underlaps the double entrance of the 

 Eustachian tubes in front. A decided dimple is found in front of 

 the sessile and superiorly notched occipital condyle, while the fora- 



' Fig. 17 



Fig. i6 Rear view of the skull of Spatula clypeata 



Fig. 17 I'osteiioi- v;ew of the skull of C 1 a n t, u 1 a islandica. Both figures 

 drawn natmal size from the specimens by the arthor. Mandibles removed. Letters 

 as ir. previous figures 



men magnum is large, of a cordate outline, with its apex directed 

 upward [see fig. 15]. 



Laterally we find the descending temporal wings, with the usual 

 group of foramina to the inner side of each, at the base of quite a 

 well marked little fossa. 



The plane of the foramen magnum makes an angle of about 45° 

 with the backwardly produced plane of the basis cranii. 



A posterior aspect of the skull of this duck shows a conspicuous 

 supraoccipital prominence, with a large, vertical, and elliptical 

 foramen opening into the cranial casket on either side 

 of it. The occipital area is well divided off from the crotaphyte 

 fossae bv a raised ridge which surrounds it. These last named 

 depressions are separated in the median line by quite an extensive 

 interval. I believe thev never meet in any true duck. 



