CLANGULA.—NOMONYX. 927 
all shy, this species is difficult to procure, as it dives at the flash of a gun and 
is extremely rapid in its movements. The food consists of fish, molluscs, freshwater 
plants, &c. The flesh is much esteemed by some people as an article of food. 
Subfam. FRISMATURINA. 
This subfamily comprises the stiff-tailed Diving-Ducks, which are closely allied to 
the Fuliguline, but differ in having the tail-feathers narrow and very rigid, as is pointed 
out by Count Salvadori. 
NOMONYX. 
Nomonyzx, Ridgway, Pr. U. 8S. Nat. Mus. iii. p. 15 (1880) ; Salvad. Cat. Birds Brit. Mus. xxvii. 
p- 488 (1895). 
This genus, represented by a single Tropical-American species, may be distinguished 
from most of the Diving-Ducks by the narrow tail-feathers, which are also very stiff. 
From Erismatura it differs in having the nail of the bill perpendicular. 
‘1, Nomonyx dominicus. 
Anas dominica, Linn. Syst: Nat. i. p. 201°. 
Erismatura dominicus, Scl. P. Z. 8S. 1857, p. 2067; 1860, p. 254°; Lawr. Mem. Bost. Soc. Nat. 
Hist. p. 316°; Scl. & Salv. P. Z.S. 1876, p. 405 °. 
Nomonyx dominicus, A. O. U. Check-l. N. Amer. Birds, 2nd ed. p. 60°; Salvad. Cat. Birds Brit. 
Mus. xxvii. p. 4387; Salvad. & Festa, Boll. Mus. Zool. Torino, xiv. no. 339, p. 13°. 
Supra niger, plumis singulis castaneo late marginatis; alis brunnescenti-nigris, tectricibus majoribus et 
dimidio externo basali secundariorum extimorum albis, speculum alare formantibus ; rectricibus nigris ; 
capite nigro; collo saturate castaneo, pectore pallidiore, abdomine albicanti-fulvo; hypochondriis nigris ; 
maxilla et area nuda oculari cyaneis, illa nigro apicata; mandibula rufescenti-alba, ad apicem nigra; 
mento nudo nigro; pedibus brunneis, tarso extus et digitis externis saturatioribus. Long. tota circa 15:0, 
ale 5°7, caude 4:0, culm. 1°25, tarsi 1°15. (Descr. maris adulti ex Peru. Mus. nostr.) 
Q. Supra saturate brunneus, fulvo maculatus; alis sicut in mari coloratis, sed tectricibus alarum medianis 
et majoribus fulvo maculatis; cauda nigricante; pileo et capitis lateribus saturate brunneis ; supercilio 
angusto et fascia latiore lorali ad occiput extensa fulvis; corpore subtus brunneo, plumis singulis fulvo 
vel albido marginatis, quasi marmoratis ; mento et gutture pallide fulvis ; collo fulvo, brunneo maculato : 
rostro brunneo, apice nigro. Long. tota circa 14:0, ale 5:6, caude 3°8, culm. 1:2, tarsi 1-1. (Deser. 
feminz adulte ex Sarayacu, Ecuador. Mus. nostr.) 
Juv. femine adulte similis, sed gastrei plumis basaliter pallidioribus. 
Hab. Norta America, Gulf Coast to the Lower Rio Grande; accidental in Wisconsin 
and on Lake Champlain, Massachusetts °.—Merxtco, Jalapa, Vera Cruz (Sallé2 3), 
Tepic (Grayson *); Guatemata?; Panama, Veragua (Arcé®7), Laguna de Pita 
(Festa ®).—TropicAL AMERICA generally, south to Chile and Argentina’; West 
INDIES /. 
The Masked Duck has been recorded from various widely separated localities in 
29* 
