LEPTODON,—REGERHINUS. 101 
albo stricte terminata et griseo (subtus albo) trifasciata: rostro nigro; mandibula, cera et loris 
nudis, cinerascentibus ; pedibus plumbeis; iride brunnea. Long. tota circa 21:0, ale 13:0, caude 10-0, 
tarsil*8. (Descr. femine ex Izalam, Yucatan. Mus. nostr.) 
Juv. Supra fusco-niger, capite toto et cervice concoloribus, plumis ad basin albis : subtus plumis medialiter fusco- 
nigricantibus, subcaudalibus albis medialiter rufis. 
Junior. Fuscus, plumis stricte fulvo limbatis, capite summo nigro ; fronte, superciliis, cervice postica et corpore 
subtus albis. 
Hab. Mexico, Tampico (Richardson), Jalapa (de Oca), Tlacotalpam !*, Santa Efigenia ’, 
Cacoprieto, Tapanatepec 12, Oaxaca (Sumichrast), Mirador (Sartorius 1+), Tonala in 
Chiapas (Richardson), Izalam in Yucatan (Gaumer !8) ; British Honpuras, Orange 
Walk (Gaumer), Cayo in the Western District (Blancaneaur); GUATEMALA 
(Constancia 14), Escuintla (0. S. & F. D. G.) ; Honpuras (Mus. Brit, 1°), San Pedro 
(Leyland *); Nicaracua, San Emilio, Lake of Nicaragua (Richardson); Costa 
Rica (v. Frantzius*), Nicoya (E. Arcé), Pozo Azul de Pirris, Birris de Cartago 
(Zeledon), Talamanca (Gabb!); Panama, Volcan de Chiriqui, Bugaba ® (#. Arcé), 
Lion Hill (M‘Zeannan *).—Sovurtn America, tropical parts generally 1°. 
Leptodon cayennensis is well known throughout Central and ‘Tropical South 
America, but is nowhere common. The species occurs in various parts of Mexico, where 
Sumichrast !2 considers it to be resident, as he obtained a female, in May 1871, whose 
ovary contained eggs nearly ready for extrusion ; he states that the bird inhabits forests, 
selecting trees of the thickest foliage and feeding chiefly on molluscs ; it frequents also 
the neighbourhood of seas and rivers. From its habit of searching the ground for 
gastropods, the bill, feet, and plumage are often much soiled. 
Specimens from every Central-American State from Mexico to Panama, Salvador 
excepted, are in our collection. 
REGERHINUS. 
Regerhinus, Kaup, Mus. Senckenb. iii. p. 262 (1845) ; Ridgway, Bull. U. S. Geol. & Geogr. Surv. 
li. p. 156. | 
Leptodon, pt., Sharpe, Cat. Birds Brit. Mus. i. p. 329. 
This genus differs from the preceding one in having the cutting-edge of the upper 
mandible without indentations. Other characters pointed out by Mr. Ridgway are 
the differently shaped bill, the weak feet, and the more compressed toes and claws. 
The plumage is soft as in the allied genera of Kites; the feathers of the lower surtace 
of the body are very broad, with nearly truncate tips. The stages of plumage passed 
through by members of this genus are difficult to account for, but after careful study we 
are inclined to believe, with Dr. Sharpe, that they are produced by a gradual alteration 
in the pattern of the feathers effected without moulting. In this and the allied forms 
melanistic examples of young and old birds are frequently met with. 
Three species of Regerhinus are recognized, all of them peculiar to the Neotropical 
Region. &. uncinatus has a very wide range in Southern and Central America, 
