150 
Genus GAMPSONYX, Y iGrOKS. 
Gampsomjx Vigors, Zodl. Jouru. ii, 18*25, p. 69. Type, G. sicainsoni Yig. 
Chondrohierax Less, (fide Sharpe, Cat. Acc. Brit. Mas. 1874, 340). 
Ch.—S imilar to Elanus , but much smaller, and differing in relative 
proportions of different parts. Colors more varied. Tail more than 
two-thirds as long as the wing; scales of the feet larger, the upper 
surface of the toes having transverse scutelhe to their bases. 
This genus is very closely related to Elanus, so much so in fact that 
it may be questioned whether it is not merely subgenerically distinct, 
since they have so many features iu common. These two genera also 
agree with the genus Nauclerus of Africa in so many points in which all 
three differ from other Falconidce that they seem to form a very well- 
defined group, which may be termed the Elani , and which may be char¬ 
acterized by the following peculiar features common to the three genera. 
Group Elani. 
Ch.—C laws not grooved beneath, their under surface being merely 
flattened, or even rounded.* Two, or none , of the outer quills with 
their inner webs sinuated.t Tarsus without any transverse scutellm, being- 
covered nearly uniformly with small roundish or hexagonal scales. 
Outer toe appreciably shorter than the inner (qu. in Nauclerus ?). 
Nostril broadly ovate, nearly horizontal, situated in the middle of the 
cere. 
The three genera differ from each other as follows :— 
A. Tomia without indentations. Tarsus about equal to, or just appre 
ciably longer than, the middle toe; second or third quill longest 
outer two with inner webs sinuated near their end. Tail much 
shorter than the wing, double rounded. 
a. Tail less than two-thirds the wing. Scales of the feet very minute, 
there being transverse scutelhe only on the terminal phalanx of 
the toes. . .. . Elanus • 
l). Tail more than two-thirds the wing. Scales of the feet larger, the 
transverse scutelhe of the toes extending nearly to their base. 
. Gampsonyx. 
B. Tomia distinctly indented. Tarsus considerably longer than the 
middle toe. First quill longest; none sinuated.% Tail nearly 
equal to the wing, excessively forked, the outer feather about 
twice as long as the inner, and much attenuated. Scales of the 
feet rough, hexagonal; transverse scutelhe only on the terminal 
phalanx of the toes . . Nauclerus .§ 
* Pandion is the only germs which shaves this feature, but in it the claws are con¬ 
tracted in thickness toward the under side, which is not the case iu the Elani, while 
all the'claws are of equal length. 
t Excepting certain Penies, as Elanoidcs and Baza, no other Buteomncc have less than 
three primaries with their inner webs sinuated. The Femes differ from the Elani, 
however very essentially, in their bony structure, lacking the superciliary shield or 
accessory piece to the lachrymal, which is simple and almost rudimentary, asm Pandion. 
t The only instance, to our knowledge, iu the entire family. 
6 The svucnymy and chai actors of this remarkable genus are as follows :— 
Nauclerui Vigors, Zodl. Journ. ii, 1825, 386. Type, Elanoidcs riocouri Vieill. 
Chelictinia Lesson, 1843 (teste Gray, ubi ?). Same type. 
Chelidopteryx Kactp, Mus. Senck. m, 1845, 2o8. Same type. 
Cmelopten/x Kaup, Weigm. Archiv.xvi, 1850, 31. 
CH.—Bili much as in Ictinia, but less robust; nostril unusually large, oval, obliquely 
