220 ANATIDA. 
1. Nyroca americana. 
Fuligula americana, Eyton, Mon. Anat. p. 1551; Scl. & Salv. P. Z. S. 1876, p. 400 . 
Aythia americana, Dugés, La Nat. i. p. 142°. 
Aytha americana, Lawr. Mem. Bost. Soc. Nat. Hist. ii. p. 315 *. 
ZEthyia americana, Baird, Brewer, & Ridgw. Water-Birds N. Amer. ul. p. 36 ‘s 
Aythya americana, Herrera, La Nat. (2) i. pp. 187°, 8297; A.O. U. Check-l. N. Amer. Birds, 
2nd ed. p. 52°. 
Nyroca americana, Salvad. Cat. Birds Brit. Mus. xxvii. p. 340°. 
Supra nigra, dorso minute albido fimbriato, dorso postico saturatiore, uropygio et supracaudalibus nigris ; 
tectricibus alarum saturate griseis, paullulum albo vermiculatis; tectricibus primariorum et primariis 
apicem versus saturate brunneis, his aliter cinerascentibus ; secundariis externis pallide griseis, 
anguste albo terminatis et fascia subterminali nigra notatis; secundariis interioribus argentescenti- 
griseis, extus anguste nigro marginatis, intimis saturate brunneis ; rectricibus saturate brunneis, 
pallide brunneo marginatis; pileo et collo superiore ]«te castaneis, hoe purpureo nitente ; colle 
inferiore, praepectore et pectore summo nigris, hujus plumis albo marginatis ; corpore reliquo subtus 
albo, abdomine fusco vermiculato; crisso et subcaudalibus fuscis, harum longioribus ad apicem albo 
marmoratis : rostro pallide ceruleo, ad apicem nigro; pedibus cerulescenti-griseis ; iride rubra. 
Long. tota circa 19-0, alze 9°3, caudw 2°7, culm. 1-9, tarsi 1:65. (Descr. maris adulti ex Zacatecas. 
Mus. nostr.) 
9. Supra brunnea, plumis singulis rufo marginatis; dorso medio et imo albo vermiculatis ; uropygio nigro ; 
alis caudaque sicut in mari coloratis; capite et collo sordide castaneo-brunneis, pileo saturatiore, mento et 
gula superiore albidioribus : prespectore cum pectoris lateribus et hypochondriis cinerascenti-brunneis, 
rufescenti-fulvo late marginatis; pectore et abdomine superiore sordide albis, vix fusco marmoratis ; 
abdomine imo crissoque brunnescenti-fulvis : rostro et pedibus sicut in mari coloratis ; iride flava. 
Long. tota circa 16°5, ale 8-7, caude 2:5, culm. 1°8, tarsi 1:6. (Deser. feminse adulte ex Corpus Christi. 
Mus. nostr.) 
Hab. Nortn America, breeding from California, Southern Michigan, and Maine 
northward §.—Mexico, Chihuahua, Boca Grande, Janos and Conalitos Rivers 
(Kennerly®), Mazatlan (Grayson *), Zacatecas (Richardson °), Guanajuato, Guada- 
lajara (Dugés*), Valley of Mexico (Le Strange? ®, Herrera ®*). 
This species is very nearly related to the Red-headed Pochard of the Old World 
(NV. ferina), but the latter differs in having no distinct purplish gloss on the head and 
neck, and the under surface of the body is finely vermiculated with ashy-grey. 
N. americana is generally distributed throughout North America, breeding in high 
northern regions and wintering southward in the United States &c., at which season 
it also occurs on both the Atlantic and Pacific coasts. ‘The species has been met with 
in Mexico, but has not been recorded from any more southern locality. 
Though occasionally found singly or in pairs, this Pochard is more often seen 
during the winter season in large flocks, not associating with other species of Ducks. 
In the estuaries of the rivers the bird procures food by diving, and feeds on the 
blades and roots of the Vallisneria; but on the shallower waters of the interior its 
habits are like those of the Mallard. It also eats grass, small lizards, tadpoles, and 
shell-fish. 
