266 Mr. Vicors’s and Dr. Honsrrrrp's Description of the 
command a prospect of the country. I cannot consider it as 
migratory.” 
Tribus. Scansores. Auct. 
Fam. Psrrracipx. Leach. 
The species of this family found in Australia are numerous, 
and they exhibit a considerable variety of form. These, with 
the exception of one or two groups which are equally met with 
in some of the adjoining islands in the Pacific Ocean, are pecu- 
liar to their own continent. ‘They belong to two only of the five 
subfamilies of the Psittacidæ ; those of the Cockatoos and the 
long-tailed Parrakeets. Hitherto we have seen no example from 
Australia of the true Psittacus, Auct., of the conterminous sub- 
family of even-tailed Parrakeets, or of the Maccaws. 
Although from the general resemblance which the birds of 
this family bear to each other, it may at first sight appear dif- 
ficult to determine which are the typical and aberrant groups, it 
strikes us that we may attain a clue to this point of distinction 
by attending to the construction of the bill, and tracing out the 
. mode in which it varies from the strength and shortness appa- 
rent in some species, to the weakness and elongation exhibited 
in others. ‘The food of the Parrots consists chiefly of nuts, 
seeds, and similar vegetable substances; and the bill, which 
possesses the greatest power in breaking the hard shells or 
rinds which inclose these substances, seems to point out the 
typical pre-eminence of the groups in which it is found. This 
strength of bil may be observed to be carried to the ex- 
treme in the two subfamilies of Cockatoos and Maccaws. In 
these birds the mandibles are of considerable size and thick- 
ness, and much more deep than long; more especially the under 
mandible, which is extremely short, and bent inwards at the 
apex so as to give the bill a greater power over the substances 
which 
