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NEW YORK STATE MUSEUM 



The lower margin of the rostrum is straight, rising gently up- 

 ward as it is projected forward, being sharp below along its 

 anterior moiety. 



Anteriorly the ethmoid has an elongocordate outline, the base 

 of the figure abutting against the under side of the craniofacial 

 region. 



Mewing this skull from beneath we notice a long, narrow cleft 

 in front of the maxillopalatines and bounded on either side by a 

 dentary process of the premaxillary. This cleft is deepest behind 

 and gradually becomes shallower as it proceeds to the front, where 

 it disappears just behind the rounded mandibular apex. 



The maxillopalatines are thin, horizontal plates that are in con- 

 tact for their anterior halves in the median line, but 

 diverge as rounded, distinct processes for their posterior 

 moieties. These processes project into the wide interpalatine cleft, 

 but do not come in contact either with the palatine bones or with 

 the vomer. This latter is a long, thin plate of bone that is grasped 

 by the small ascending processes of the palatines behind to anchy- 

 lose with them, while above it is finished oft" with a riblike margin 

 which is produced beyond the plate in front as a long spiculiform 

 process, with its apex resting upon the middle of the maxillo- 

 palatine median suture. 



Each palatine body is a narrow lamina of bone, the anterior end 

 of it dilating somewhat before being inserted between and fused 

 with the other elements in front. 



These palatines only meet each other, and that only in a point, 

 behind their common seizure of the hinder end of the vomer. Xor 

 do they come in contact with the under border of the rostrum, 

 as they are prevented from doing so by the sessile, though large 

 and elliptical, basipterygoid facets found upon the latter. 



Their heads are separated behind by quite an interval, and each 

 one makes a peculiar combination joint with the corresponding 

 head of the pterygoid, which develops the reverse articulation for it. 



Immediately posterior to this a pterygoid supports also a sessile 

 elliptical facet of precisely the same character as the one referred 

 to above as occurring on the rostrum, the two coming in contact 

 to form a perfect sliding joint, with smooth and plane surfaces 

 opposed to each other. 



Posterior to this articulation a pterygoid is somewhat compressed 

 from above downward, and curves gracefully outward to cover 

 with its cuplike hinder end the spheroidal facet offered to it on 

 the part of the corresponding quadrate. 



