153 
Loral feathers very compact, imbricated, and without bristly 
tips. Tomianot toothed. Pernis. 
Loral leathers moderately compact, or even scattered, not imbri¬ 
cated, and with bristly tips. Tomia toothed. 
§. Four outer primaries with inner webs sinuated_ Leptodon. 
§. Two outer primaries with inner webs sinuated. Baza. 
b. Bill greatly hooked, and much compressed. Feathers of the 
pileum soft and blended, without tendency to greater elonga¬ 
tion on the occiput. Lores naked, crossed by a narrow line of 
fine bristles from the anterior angle of the eye to the fore¬ 
head... Regerhinus. 
B. Cere not tumid, the nostril broady oval, without overhanging 
membrane. Tail excessively forked, about equal to the wing. 
Inner webs of only two outer quills sinuated. Tomia with¬ 
out indentations. Lores densely feathered. Elanoides. 
The transition from Leptodon to Baza , through Avicida , may be ex- ' 
pressed by the following tabulation of the main characters of the three 
genera: 
A. Five outer primaries with inner webs sinuated. 
a. Tail much rounded. Primaries but little longer than secondaries. 
Lores scantily feathered. Indentations of the tomia a simple 
tooth and notch. Occipital crest rudimentary. Leptodon. 
b. Tail nearly even. Primaries considerably longer than the secon¬ 
daries. Lores scantily or compactly feathered. Indentations 
of the tomia simple or double. Occipital crest rudimentary or 
moderately developed. Avicida* 
B. Two outer primaries with their inner webs sinuated. Loral 
feathers very compact. Indentations of the tomia double. 
Occipital crest very long. Baza. 
The apparently wide difference between Leptodon and Pernis in the 
feathering of the lores is most perfectly made up by the varying character 
of the species in the genus (or subgeuus) A vicida , the three species we 
have been able to examine varying as follows:— 
A. subcristata.— Loral feathers compact. Indentations of the tomia 
double. 
A. verrcauxi.— Loral feathers scant. Indentations of the tomia double. 
A. cucnloides.—Loral feathers scant. Indentations of the tomia 
simple. 
Thus, in A. subcristata , the loral feathers are only a little less compact 
than in Baza, in which they are rather less dense than in Pernis. In 
the other two species they are still less dense, though more so than in 
Leptodon (as most restricted); while one of the species of Avicida agrees 
with Leptodon in the simple indentations of the tomia. Nearly all of 
these birds, including Pernis , have more or less of a tendency in a few 
of the occipital feathers to form a crest, which in Leptodon is constantly 
rudimentary, and in the species of Avicida and Pernis frequently so. 
LEPTODON CAYENNENSIS. 
I'atco cayennensis Gmelin, Syst. Nat. i, 1788, 269 (not of p. 263!), (adult).—L ath. 
Index Orn. i, 1790, 28; Gen. Hist, i, 1824, 269.— Baud. Tr. Ont. ii, 1800,74.— 
Siiaw, ZoOl. vii, 161 .—Temm. PI. Col. i, 1»24, pi. 270; Tab. Mdth. 4. 
* Avicida Swainson, Birds \V. Africa, i, 1837,104. Type, A. cuculoides Swains. 
This genus includes also A. suberistatus (Gould) and A. verrcauxi Lafr., and probably 
others, since Mr. Sharpe includes in the genus “Baza'’ ten species, of which we cannot 
state positively that more than one, B. Jophotes, is a true Baza, not having seen most 
of the species described. 
No. 2-5 
