SCAUP DUCKS AND ALLIED SPECIES. 97 



tarsus compressed ; hind toe slender, with a pretty large mem- 

 brane ; outer toes about equal, and nearly double the length 

 of the tarsus ; interdigital membranes full ; claws small, 

 compressed, obtuse ; wings rather short, convex, narrow, 

 pointed, the first and second quills longest ; tail very short, 

 much rounded, or tapering, of fourteen or sixteen stiffish, 

 narrow feathers. 



1. Oidemia perspicillata. Surf Scoter. Bill mostly 

 orange-red ; upper mandible with a nearly square patch on 

 each side at the base, margined anteriorly with a bluish- 

 white space, unguis greyish-yellow ; feet orange -red, with 

 dusky membranes ; plumage black ; a patch of white on the 

 top of the head, another on the hind-neck. 



2. Oidemia fusca. Velvet Scoter. Bill with the base 

 and margins of both mandibles black, the unguis of both red, 

 the sides of the upper orange ; feet orpiment-orange on the 

 inner, lake-red on the outer side; plumage black ; speculum, 

 and a spot below the eye, white. 



3. Oidemia nigra. Black Scoter. Bill black, with an 

 orange-yellow patch on the upper mandible, including the 

 nostrils ; feet dusky ; plumage entirely black ; first quill very 

 narrow. 



GENUS IV. SOMATERIA. EIDER. 



Bill nearly as long as the head, higher than broad at the 

 base, becoming depressed toward the end, where it is consi- 

 derably narrowed, but rounded ; upper mandible with the 

 lateral sinuses very large, the upper long and very narrow, 

 the frontal angles elongated, soft, and tumid, the sides erect 

 at the base, the edges thin, concealing the not very numerous 

 slender lamellae, the unguis extremely large, elliptical, con- 

 vex, moderately decurved ; that of the lower mandible very 

 large, broadly elliptical, little convex ; legs very short ; tarsus 

 compressed ; hind toe slender, with a broad lobiform mem- 

 brane ; outer toes nearly double the length of the tarsus ; 

 interdigital membranes emarginate ; claws small, compressed, 

 obtuse ; wings rather short, very convex, narrow, pointed, 

 the first and second quills longest ; inner secondaries elon- 



VOL,. Y. H 



