This peculiar species may always be recognized by the brownish or chestnut upper parts, blackish crown, white cheeks and silvery white underparts. The bill is very stout and broad at the end, and the tail feathers are stiff and pointed like those of a Cormorant. They build their nests in low marshy places, either placing them on the ground near the water or in the rushes over it. Their nests are made of rushes and grasses, sometimes lined and sometimes not, with down from the parents breast. The eggs number from six to twelve and are grayish in color. Size 2.40 × 1.75. Data.--Northern Assiniboia, Canada, June 6, 1901. Eight eggs. Nest made of aquatic grasses, lined with down. Built in a tuft of rushes in a marsh. Collector, Walter Raine. 168. MASKED DUCK. _Nomonyx dominicus._ This is a tropical species which is resident in Mexico, Central America and in the West Indies. It occurs in Mexico north to the lower Rio Grande Valley and has in three known instances strayed to northern United States. The general plumage is a rusty chestnut, mottled with blackish, it has a black face and throat, with white wing bars. [Illustration 108: Grayish white.] [Illustration: Ruddy Duck. Masked Duck.] [Illustration: deco.] [Illustration: left hand margin.] Page 107 169. SNOW GOOSE. _Chen hyperboreus hyperboreus._ Range.--North America west of the Mississippi Valley, breeding in northern Alaska and the MacKenzie River district. This smaller species of the Snow Goose nests on islands in rivers along the arctic coast. The nest is a depression in the ground, lined with grasses and, occasionally down. They lay from four to eight eggs of a buffy or yellowish white color. Size 2.75 × 1.75. 169a. GREATER SNOW GOOSE. _Chen hyperboreus nivalis._ Range.--Eastern North America, breeding in the Arctic regions and wintering chiefly on the Atlantic coast, south to Cuba. This bird is like the preceding; except in size; about thirty-six inches, instead of twenty-six inches in length as is the lesser variety. The entire plumage is white except for the black primaries. They construct their nests of grasses on the ground the same as the preceding variety. The eggs number from five to eight and are cream colored. Size 3.40 × 2.40. 169.1. BLUE GOOSE. _Chen cærulescens._ Range.--North America, principally in the interior, breeding from Hudson Bay northward and wintering along the Gulf coast. This species may always be recognized by the entirely white head and neck, the body being grayish or bluish gray. They nest on the ground as do the other geese laying from four to eight eggs of a brownish buff color. Size 2.50 × 1.75. Data,--Cape Bathurst, Arctic coast, June 29, 1899. Four eggs laid in a depression lined with grass, on an island. Collected with the parent birds by the Esquimaux. [Illustration 109: Grayish White.] [Illustration: Lesser Snow Goose. Blue Goose.] [Illustration: right hand margin.] Page 108 170. ROSS'S SNOW GOOSE. _Chen rossi._