WHITE-TAILED HAWK. 
381 
genus Falco. It participates in the form and habits of the 
kites (Milvus)^ while in its other relations it approaches the 
true falcons (Falco) ^ and at the same time presents traits pe- 
culiar to itself. Savigny has, therefore, very properly consi- 
dered its near relative, the black-winged, as the type of a pe- 
culiar group, which he elevates to the rank of a genus, but 
which we for the present shall adopt as a subgenus only. Sub- 
sequent observations have confirmed Le Vaillant’s opinion, that 
the swallow-tailed hawk (Falco furcatus) is closely related to it; 
and associated with a few other recently discovered species, 
they have been considered as a distinct group, under Savigny’s 
name of Elanus, Vieillot adopted the group as a genus, but, 
for what reason we know not, has since changed the name to 
Elanoides, The hawks of this group are readily distinguished 
from all others, by the superior length of the second primary 
of their elongated wings ; by their bill, rounded above, cur- 
ved from the base, and not toothed ; their hirsute cere ; thick, 
short, and wholly reticulated tarsi, half feathered before ; toes 
entirely separated, and powerful nails. The head is flattened 
above, the gape wide, and the eyes large, deep sunk, and 
with the orbits greatly projecting above. The colours are also 
similar in the different species, being white, or pale, (bluish 
white, &c.) with more or less of black. The comparatively 
even tail of the two allied species of which we are treating, 
eminently distinguishes them from the others of the subgenus, 
which have the tail exceedingly forked. They are remarkable 
also for another characteristic, that of having the nails rounded 
beneath, and not canaliculate, a circumstance that occurs be- 
sides only in the subgenus PandionJ^ This character, which 
we formerly attributed to all the Elani, and which we believe 
we first observed not to exist in the fork -tailed species, has 
induced Mr Vigors, the English ornithologist, to separate the 
latter as a new genus, under the name of Nauclerus, 
* In Pandion, however, it is the middle nail that is rounded ; in this species^ 
it is the lateral and posterior only. 
