148 MNIOTILTID ZA. 
its being not common near Mazatlan, where it frequents stagnant pools or solitary 
brooks. 
In North America, where it is only known as a summer visitant, its chief resort is 
the Southern and South-western States, appearing only as a straggler in more northern 
districts. It is one of the earliest Warblers to arrive, and may be heard in full song 
from the end of February. Its song is distinguished by the richness and power of its 
note 4, Not much seems to be known of itsnest and eggs, as Brewer’s account of them 
is taken from Audubon #4, . 
As in the case of the two preceding species, its literature is fully given in Dr. Coues’s 
volume 4. 
OPORORNIS. 
Oporornis, Baird, B. N. Am. p. 246 (1858). (Type Sylvia agilis, Wils.) 
The members of this genus much resemble some of the next following, the style of 
colour being much the same. They have, however, the wing pointed and longer than 
the tail, in which character they agree with Siwrus. The bill has a distinct notch, the 
rictal bristles very short, the tail nearly even, the feathers acuminate, and the under 
coverts long. The tarsi are long, and the claws large. 
Two species are known of the genus, whereof one, O. formosa, enters our fauna as 
a winter visitant. Of the other, 0. agilis, the history is by no means complete. It is 
not known to have occurred beyond the borders of the Eastern States; and though not 
uncommon at certain seasons in Massachusetts, its breeding-haunts have not yet been 
detected. 
1. Oporornis formosa. 
Sylvia formosa, Wils. Am. Orn. iii. p. 85, t. 25. f. 3%. 
Oporornis formosa, Scl. & Salv. Ibis, 1859, p. 10°; P.Z.S. 1864, p. 847°; Scl. P.Z.S. 1862, 
p. 19*; Lawr. Ann. Lyc. N.Y. vii. p. 468°, ix. p. 94°; Bull. U.S. Nat. Mus. no. 4, p. 167; 
Baird, Rev. Am. B.i. p. 218°; Dresser, Ibis, 1865, p. 477°; Salv. P. Z. S. 1867, p. 186”; 
Frantz. J. f. Orn. 1869,"p. 293"; Baird, Brew. & Ridgw. N. Am. B. i. p. 293"; Gundl. Orn, 
Cub. p. 68; Coues, B. Col. Vall. i. p. 809 ™. . 
Supra olivaceus, alis caudaque concoloribus; capite summo loris et genis nigris, illo olivaceo transfasciato ; 
superciliis, oculorum ambitu parte postica et corpore toto subtus flavis; rostro corneo, mandibule basi 
flavicante ; pedibus carneis. Long. tota 4°8, alee 2°75, caude 2:0, rostri a rictu 0°6, tarsi 0-9. (Deser. 
exempl. ex Coban, Guatemala. Mus. nostr.) 
2 mari similis, colore nigro capitis absente. (Descr. feminw ex Chiriqui, Panama. Mus. nostr.) 
Hab. Nortu America, Eastern States from the Mississippi valley eastwards ? 14, Texas ®. 
—Me_xico, Playa Vicente (Boucard*), Guichicovi (Sumichrast’); GusTEMALA 2, 
Duefas, Calderas, Coban, Choctum (0. 8. & F. D. G.); Costa Rica !, Angostura, 
