100 FALCONID. 
water. Salvin noticed an immense flight of these Hawks migrating in a north-westerly 
direction along the Pacific coast-region of Guatemala, in March 1858, where it is well 
known to the Spaniards under the name of the “ Asacuani”; and the term has become 
proverbial for a person constantly wandering from place to place *. Leyland obtained a 
specimen near the Lake of Peten. The food consists almost entirely of univalve 
molluscs. Dr. A. K. Fisher! says that in Florida the species on which it subsists 
(Ampullaria depressa) is two or three inches in diameter. Having captured one, it 
perches and removes the animal without injuring the shell; five or six are thus secured 
before the bird, retaining them in the gullet, returns to feed its young. 
In South America, Mr. Hudson says, R. sociabilis arrives in Buenos Ayres in 
September, where it breeds in flocks. ‘The nest is described by Bendire 1° as carelessly 
constructed, the base consisting of dry willow-branches some half an inch in diameter, 
the cavity being seven inches wide by one and a half deep, and lined with small vine- 
stems and willow-twigs. 
The eggs, numbering two or three, are laid between the latter part of February and 
the early part of May. They are pale greenish-white, with brownish-red blotches 
sometimes entirely concealing the ground-colour. 
LEPTODON. 
Cymindis, Cuvier, Régn. An. i. p. 319 (1817) (nec Latr.). 
Leptodon, Sundevall, K. Vet.-Ak. Handl. 1835, p. 114; Sharpe, Cat. Birds Brit. Mus. 1. p. 329 ; 
Ridgw. Bull. U. 8S. Geol. & Geogr. Surv. i. p. 153. 
The genus Leptodon contains but two species—one, L. cayennensis, being widely 
distributed throughout South and Central America; the other probably confined to 
Eastern Brazil. It is placed by Dr. Sharpe at the end of his subfamily Aquiline, 
among the Kites which have a rounded tail. The bare face is also a peculiarity; and 
Mr. Ridgway further points out that the mandible is distinctly toothed, a character 
which distinguishes Leptodon from Regerhinus. 
1. Leptodon cayennensis. 
Cayenne Osprey, Lath. Gen. Syn. 1. p. 47". 
Falco cayennensis, Gm. Syst. Nat. i. p. 263’; Temm. Pl. Col. 270’. 
Cymindis cayennensis, Moore, P.Z. 8. 1859, p. 52°; Scl. & Salv. Ibis, 1859, p. 219°; Lawr. Ann. 
Lye. N. Y. vii. p. 317°; Bull. U. S. Nat. Mus. no. 4, p. 42"; v. Frantz. J. f. Orn. 1869, 
p. 369°; Salv. P. Z. S. 1870, p. 216°. 
Leptodon cayennensis, Sharpe, Cat. Birds Brit. Mus. i. p.333°; Ridgw. Bull. U.S. Geol. & Geogr. 
Surv. ii. p. 153"; Sumichrast, La Nat. v. p. 287; Boucard, P. Z. S. 1883, p.457"; Salv. 
Cat. Strickl, Coll. p. 505 “; Zeledon, An. Mus. Nac. Costa Rica, 1887, p. 126. 
Supra schistaceo-niger, alis indistincte nigro transfasciatis, capite et cervice griseis: subtus albus, tibiis 
irregulariter nigro transfasciatis ; subalaribus nigris, remigibus nigris, griseo transfasciatis; cauda nigra, 
