346 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



Genus ERISMATURA Bonap. 



66. Erismatura jamaicensis (GMEL.). 

 RUDDY DUCK. 



Erismatura rubida (Wils.), A. O. U. Check List, 1895, p. 59. 

 Distr.: North America in general, from Hudson Bay, British Col- 

 umbia and Great Slave Lake to the West Indies, Mexico, Lower 

 California, and Central America; breeds nearly throughout its range. 

 Adult male in breeding plumage: Top of head and nape, black; 

 sides of head, white; chin, whitish; throat, breast, and sides of body, 



flanks and rest of upper parts, deep 

 rufous brown; wings, brown, with- 

 out white patch; axillars, grayish 

 white, with pale brown or grayish 

 brown shafts; tail, black, the 

 o .*' " <>? feathers stiff and pointed. 



Adult female: The general color 



of the upper parts is brownish gray; sides of the head and throat, 

 whitish, shading into, gray on the lower throat and upper breast; 

 under parts, silver white, as in the male. 



Length, 15.30; wing, 6; tarsus, 1.20; bill, 1.50. 

 The Ruddy Duck may easily be distinguished from other species 

 by its small size, and stiff, pointed tail feathers. It is common during 

 the migrations in spring and fall, and a few remain in summer, and 

 breed in both Illinois and Wisconsin. 



Nelson mentions young birds of this species having been seen in 

 northern Illinois, and Cooke states that it is known to breed casually 

 in Ohio and Illinois. (Bull. Biol. Survey, No. 26, 1906, p. 63.) It 

 breeds regularly in southern Minnesota and casually in Wisconsin. 

 Kumlien and Hollister state: "A few breed in the state, as about 

 Lake Koshkonong, Pewaukee Lake, Lake Horicon, etc., but sparingly 

 of late." (Birds of Wisconsin, 1903, p. 27.) 



Genus NOMONYX Ridgway. 



67. Nomonyx dominicus (LiNN.). 



MASKED DUCK. 



Distr.: Tropical America in general, including West Indies, 

 ranging north as far as southern Texas, accidental in eastern North 

 America. Stragglers have been taken in Massachusetts, New York, 

 and Wisconsin. 



