278 



to the sacrum, the first of which unites with the sternum. The mastoid has coalesced with 

 the postfrontal, and this, by continuous ossification beneath the orhit, with the lacrymal. 



Mm. Gould. 

 Genus Nestor. 



1443. The upper mandible and sheath of the lower mandible of the Hook-billed 

 Parrot (Nestor hypopolius). Presented by John Gould, Esq., F.R.S. 



Genus Calyptorhynchus. 



1444. The skeleton of the Yellow-eared Black Cockatoo (Calyptorhynchus xantlio- 

 notus). 



The number of vertebrae between the skull and sacrum is 18, and of these the last six 

 support moveable ribs, the five posterior pairs of which articulate with the sternum. The 

 orbits are small, but with an entire bony circumference, due to an extension of ossification 

 from the lacrymal to the postfrontal. The mastoid does not join the postfrontal in this 

 species. There is a small snperoccipital foramen : the paroccipitals are bent backwards. 

 The upper mandible, consisting of the coalesced nasals, maxillaries and premaxillaries, pre- 

 sents the short, deep and broad proportions, with the small circular nostrils perforated near 

 the base, and the hooked apex, characteristic of the Parrot-tribe. This mandible is articu- 

 lated below by the palatines to the vomer and presphenoid, and by the pterygoids to the 

 tympanics ; above by a transversely extended linear moveable articulation with the broad 

 frontal. The lower jaw is of unusual depth : the articular surface for the tympanic forms a 

 longitudinal groove. The aspect of the external trochlea of the metatarsus is outwards and 

 a little backwards : the toe which it supports is turned backwards, and, with the inner toe, 

 opposes the two anterior toes, thus forming the ' scansorial foot ' characteristic of the order 

 of which the Parrots are the type. 



Mm. Gould. 



1445. The skeleton of the male of the Western Black Cockatoo (Calyptorhynchus 

 nasd). 



Of the 18 vertebrae between the skull and sacrum, the six posterior bear moveable ribs, the 

 last four pairs of which unite with the sternum : there are also two pairs of sacral ribs, of 

 which the first joins the sternum. In this species there is a continuity of ossification from 

 the mastoid to the postfrontal and from this to the lacrymal. The right perforation of the 

 sternum has not been obliterated by the ossification of the aponeurotic membrane. The 

 wings are shorter and the flight less powerful and extensive in this than in the preceding 

 species. 



Mm. Gould. 



