201 
PART IV. 
SYNOPSIS OF A NATURAL ARRANGEMENT 
OF BIRDS. 
(219.) In the following Synopsis there are a few al- 
terations in the arrangement of the groups from what 
they appear in the foregoing part: this has resulted 
from further analysis, and by incorporating our re- 
searches up to the latest time. An attentive comparison 
of Gypogermius with the Polyborus Braisiliensis, and 
these again with some of the long-legged eagles, has at 
length convinced us that the first is no other than the 
rasorial type of the Aquiline circle ; the more so, as its 
long legs and elegant crest are at once explained by this 
analogy. The numerous variations in the forms of the 
eagles and the buzzards induce us, also, to adopt Mr. 
Vigors’s plan of considering the primary divisions of the 
FALcoNiDiB as so many subfamilies, rather than as genera, 
and in this group many other alterations have been made. 
Our suspicions with regard to the situation of the genus 
Pipillo have been completely verified by the new species 
subsequently described ; so that it will now be found 
(witli Arremon as a subgenus) arranged in the Tanagrine 
circle. The genus Megapodius, and not Craco, turns out 
to be the type of the rasorial division of the Rasores ; 
and Seolopax, instead of Tringa, stands at the head of the 
Grallatores. The minor alterations it is not necessary 
to particularise. 
(220.) The specific names, placed under each group 
are not always those by which the bird is mentioned in 
the work referred to ; for many of the names used by 
these authors, even when good, have not the claim of 
priority, or the birds have not been placed in the grouj) 
under which they here stand : the nomenclature, there- 
fore, must be rather considered our own, than that of 
