PsiTTACIDiE.] OSTEOLOGIA AVIUM. [Pez0P0R1NJ3. 



resembles them in the form of the palatine bones, except one among Insessores, and from 

 that they are easily distinguished by the other parts of the skeleton. The great motion 

 of the upper mandible is peculiar. The form of the sternum, in general having great 

 depth of keel in proportion to the breadth of the horizontal portion of it, has nothing 

 like it, except among Volitores. The furculum is either, although perfectly formed, 

 very weak, rudimentary, or entirely wanting ; the ribs are continued very far backwards 

 over the sides of the abdomen. The branches of the os pubis are generally very much 

 turned inwards at their points, and the posterior margin of the ischium is gradually 

 rounded towards them, from its junction with the ilium. The wing-bones are short, as 

 are also the metatarsal and other leg bones. 



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