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- 

 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. 



Relationsliips. — From its external appearance, this curious hawk con- 

 veys no suspicion of near affinity with the Falcoius, except in the 

 peculiar shape of its nostrils. The plumage has the softness of that of 

 the weaker forms of the Buteonimv (notably the genus FlarpagKS and the 

 group Femes), while the scutellation of the feet calls ;it once to mind the 

 genus Circaetus, to which Eerpetotheres 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 hallax 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 Linnc). 



HERPETOTHEEES CACHINXANS. 



LAUGHING FALCON. 



Fidco cacUUnuins LiNX. Sysf. Nat. i, 1766, 12^. 



Astur cachinnans Cl'V. Reg. An. i, 1817, 3-20.— Spix, Av. Bras, i, 1824, 8, tab. iii a. — 



SCHLEG. Mus. Pays-Bas, Astnres, 1862, 26 ; Eev. Ace. 1873, 68. 

 Hcrpefotheres cachinnans Vieill. Nouv. Diet, sviii, 1817, 317. — Vieill. &. Ocd, 



Gal. Ois. i, 1825, 47, pi. 19.— Cassix, Pr. Ac. Nat. Sci. Phila. iv, 1848, 87 (Vera 



Cruz).— BoxAP. Consp. Av. i, 1850, 30. — Strickl. Orn. Syu. i, 1855, 75.— BuRM. 



Th. Bras, ii, 1855, 90.— Sclatek, Proc. Zool. Soe. Lond. 1857, 201 (Jalapa) ; 



(7). 1868, 629 (Venezuela).— Lawr. Ann. Lye. N. Y. ix, 1868, 132 (Costa Eica) ; 



Mem. Bost. Soc. N. H. ii, 1874,300 (Mazatlan ; biographical notes).— Sumichr. 



ift. i, iv, 1869, 560 (Vera Crnz ; hot region).— Gray, Hand List, i, 1869, 31.— 



Salvix, p. Z. S. 1870, 214 (Veragna).- ScL. &.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. Ace. Brit. Mus. 1874, 278. 

 Cachlnna cachinnans Flemixg, Phil. Zool. ii, 1822, 236. 

 Dadalion cachinnans VIGORS, Zool. Journ. i, 1824, 338. 

 ^acar/»a (?«(7(i?i««)is LESS0X,Trait(5 Orn. 1831, 63. 

 Circai'tus cachinnans Kaup, Mus. Senck. iii, 184-5, 260. 

 CacMnna herjcelotheres Gray, Gen. B. i, 1845, 15, pi. 7, fig. 4. 

 Macagud Azara, Pax. Par. i, 1802, 81.— Hartl. Ind. Azara, 1847, 2. 



Hah. — Entire intertropical region, from Mazatlan, Tehuantepec, and 

 Vera Cruz to Bolivia and Paraguay. Xot recorded from the Andean 

 district. 



Wing, 10.60-11.80; 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. Adnlt : — Head, neck, entire lower parts, and 

 longer upper tail-coverts pale ochraceous or ochraceouswhite; 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- 



^^0. L"* 1 



