137 
bristled ; lores densely bristled ; loral and frontal bristles invading the 
cere so as to almost cover it, especially on the upper surface, where 
they grow to the anterior edge; superciliary shield bare. Wing mod- 
I erate, rounded, but the primaries straight; the primaries soft and 
obtuse ; fourth quill longest; first about equal to the ninth ; inner webs 
of the outer four distinctly sinuated, the sinuation disappearing on the 
sixth. Tail a little shorter than the wing, much rounded, the feathers 
soft and appreciably tapering toward the rounded ends. 
Relationships. —From its external appearance, this curious hawk con¬ 
veys no suspicion of near affinity with the Falconcs, except in the 
peculiar shape of its nostrils. The plumage has the softness of that of 
the weaker forms of the Buteoninw (notably the genus Earpagus and the 
group Femes), while the scutellation of the feet calls :it once to mind the 
genus Circaetus, to which Eerpetotlieres bears the closest resemblance in 
its general aspect. Yet with this ignoble appearance when in death or 
when at rest, this species exhibits, when aroused, an irritability and 
spirit said to exceed even that of the true falcons. The bony structure 
of this form shows at once its very close affinity with the Falcones , the 
osteology presenting only very slight differences, the most important of 
which is the greater elongation of the hallux compared with the length 
of the lateral toes. 
This form is of arboreal habits, and subsists chiefly on reptiles. 
Only one species is known, the Laughing Falcon of the older authors 
(Falco cachinnans Linne). 
HEKPETOTHERES CACHINNANS. 
LAUGHING FALCON. 
Falco aachinnans Linn. SysL Nat. i, 1766, 123. 
Astur cachinnans Cuv. Reg. An. i, 1817, 320. — Spin, Av. Bras, i, 1824, 8, tab. iii a .— 
Sen leg. Mas. Pays-Bas, Astaires, 1862, 26 ; Rev. Acc. 1873, 08, 
Hcrpetotheres cachinnans Yieill. Nouv. Diet, xviii, 1817, 317. — Vieill. A Oun, 
Gal. Ois. i, 1825, 47, pi. 19.— Cassin, Pr. Ac. Nat. Sci. Phila. iv, 1848, 87 (Vera 
Cruz).— Bonap. Consp. Av. i, 1850, 30.— Strickl. Orn. Syn. i, 1855, 75.— Burm. 
Th. Bras, ii, 1855, 90. — Sclater, Proc. Zool. Soc. Lond. 1857, 201 (Jalapa) ; 
ib. 1868, 629 (Venezuela).— Lawk. Ann. Lyc. N. Y. ix, 1868, 132 (Costa Rica); 
Mem. Bust. Soc. N. H. ii, 1674, 300 (Mazatlan ; biographical notes). — Sumichr. 
ib. i, iv, 1869, 560 (Vera Cruz ; hot region).— Gray, Hand List, i, 1869, 31. — 
Salvin, P. Z. S. 1870, 214 (Veragua). — Sen. & Salv. ib. 838, (coast Honduras); 
Norn. Neotr. 1873, 122.— Pelz. Orn. Bras. 1871, 7, 398. — Ridgw. Pr. Bost. Soc. 
N. H. 1873, 52. — Sharpe, Cat. Acc. Brit. Mus. 1874, 278. 
Cachivna cachinnans Fleming, Phil. Zool. ii, 1822,236. 
Dadalion cachinnans Vigors, Zool. Journ. i, 1824, 338. 
Macagua cachinnans Lesson, Traitd Orn. 1831, 63. 
Circaetus cachinnans Kaup, Mus. Senck. iii, 1845, 260. 
Cachinna herpetotheres Gray, Gen. B. i, 1845,15, pi. 7, fig. 4. 
Macagnd Azara, Pax. Par. i, 1802,81. — Haiitl. Iud. Azara, 1847,2. 
Hah .—Entire intertropical region, from Mazatlan, Tehuantepec, and 
Vera Cruz to Bolivia and Paraguay. Not recorded from the Andean 
district. 
Wing, 10.G0-11.80; tail, 8.50-10.00; culmen, 0.85-1.00 ; tarsus, 2.15- 
2.60; middle toe, 1.60-1.90. Third to fifth quill longest; first equal to 
or longer than the ninth. Adult :—Head, neck, entire lower parts, and 
longer upper tail-coverts pale ochraceous or ochraceous-white; feathers 
of the pileum with black shaft-streaks. A broad patch or “spectacle” of 
black on the side of the head, involving the posterior half of the lores, the 
orbital region, cheeks, and auriculars, and extending thence around the 
upper part of the nape in a broad, abruptly-defined collar, leaving an 
equally well-defined nuchal collar of ochraceous or whitish below it. 
Upper surface, in general, blackish-brown, the primaries much varie- 
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