156 
Genus REGERHINUS, Kaup. 
Regerhinus Ivaup, Mus. Senck. iii, 1845, 262. Type, FaJco uncinatus Illig. 
Cymindis Swains. 1837, et auct. (uec. Cuv. 1817). 
Ch.*—F orm very light; the feet very weak (almost Steatoruithine); 
bill very large, greatly hooked, and much compressed; wings and tail 
large, the latter slightly rounded. Toinia without indentations or per¬ 
ceptible sinuations; gouys nearly straight; tomium of the lower man¬ 
dible very convex. Nostril very small, slit-like, narrower, and more 
horizontal than in Leptodon. Tarsus about equal to the middle toe, 
covered with large, irregular, hexagonal scutelhe (as in Leptodon and 
Manoides) ; toes and claws compressed; middle claw with its inner 
edge much produced, as in Elanoides. Eemiges and rectrices greatly 
developed, very broad, and of a soft texture. Contour-feathers of the 
inferior surface remarkably broad, their tips nearly truncated; feathers 
of the pileum soft and blended, with no tendency to an occipital crest. 
Secondaries very long and broad, about three-fourths as long as the 
primaries; third, fourth, or fifth quills longest; first shortest; outer 
six with inner webs faintly sinuated. Tail large, but much shorter 
than the wing, slightly rounded, the feathers broad and soft. Lore 
wholly naked, with a narrow strip of bristles extending from the ante¬ 
rior angle of the eye to the anterior part ot the frontal feathers, which 
extend forward so as to almost cover the top of the cere, xkfter-shatts 
better developed than in Leptodon. 
This genus is so very distinct from Leptodon that it is a matter ot 
surprise why it should ever have been considered synonymous. The 
form of the bill is entirely different and strikingly distinctive, while there 
are very conspicuous differences throughout its external structure. The 
feet are weaker than in auy of the allied genera, the toes and claws be¬ 
ing more compressed. In its pterylosis, it is more like Avicida subcris- 
tata than any other species of the group, the contour-feathers of the 
lower surface having that same remarkable breadth and nearly trun¬ 
cated termination, while the wings and tail are quite similar. There is 
also considerable resemblance in the colors and markings. In Avicida , 
however, the lore is feathered, the occipital feathers are pointed and 
crest-like, and the bill more like that of Leptodon, 
The species of this genus present so many phases of plumage that 
they are in a state of great confusion. We do not pretend to have made 
any progress toward elucidating them, but present our views so far as 
thev have resulted from the examination ot the material available. 
REGERHINUS UNCINATUS. 
Falco uncinatus Temm. PI. Col. 1824, pis. 103, 104, 115. 
Cymindis uncinatus Lesson, Man. Orn. i, 1828, 91; 
Journ. i, 337.— Stephens, Zool. xiii, 22 .—Gray, 
Tr. Orn. 1831, 
, 55.—VlG. Zool. 
Gen. B. 1845, 25, pi. 9, fig. 
Yog. 1844, 124.— Bonap. Consp. 
1870, 557 (Trinidad).—S. Pelz. Orn. Bras. 
1873, 136.— Sharpe, P. Z. S. 1873, 419. 
1871, 
* I have been unable to obtain bones of this genus, but the osteological characters 
are probably very similar to those of Leptodon and Elanoides. Nitzsch mentions nothing 
peculiar in the pterylosis. 
