THE SNOWY HERON. 167 



Length to end of tail 22| inches, to end of wings 23, to end of claws 30|; 

 extent of wings 38; wing from flexure 10§; tail 3; loose feathers \\ beyond 

 the tail; bill along the ridge 3 T 2 5 ; along the edge of lower mandible 3§; bare 

 part of tibia 2\\ tarsus 3||; middle toe 2%, its claw T %. Weight 12 oz. 



The elongated feathers of the back are composed of two scapular series, 

 and of those crossing the humerus. The mouth as in the other species. 

 Tongue 1 inch 3 twelfths long, as in the last species. (Esophagus 14 inches 

 long, at the commencement 1 inch 9 twelfths in width, contracting to 10 

 twelfths; its greatest diameter within the thorax 1 inch 4 twelfths; proven- 

 tricular belt S twelfths in breadth. Stomach remarkably small, roundish, 

 10 twelfths in diameter, with a globular pyloric lobe, 4^ twelfths in diameter; 

 its muscular coat thin, the tendons 4 twelfths in breadth; the inner surface 

 smooth and soft. Lobes of the liver lj inches and l£ inches in length; 

 gall-bladder oblong, 9 twelfths long, 5 twelfths broad. Intestine 3 feet 10 \ 

 inches long, of 24 folds; its greatest width in the duodenal part 1^ twelfths, 

 its smallest near the rectum 1 twelfth. The rectum is 2 inches 10 twelfths 

 long, 2| twelfths in breadth; the cloaca globular, l£ inches in diameter; the 

 coecum a small knob 1 twelfth long, and of the same width. 



Trachea 10 inches long, its average breadth 2\ twelfths, considerably 

 flattened; the rings 18S, with 4 dimidiate. Bronchial half rings 18 and 16. 

 Muscles as in the other species. 



FAMILY XXXIX.— ANATIN^E. DUCKS. 



Bill of moderate length, stout, straight, depressed toward the end, obtuse, 

 covered with soft skin; upper mandible transversely convex, with the mar- 

 gins internally lamellate, the tip furnished with a decurved horny broad 

 unguis; lower mandible with the angle long and narrow, the crura slender, 

 flattened, the edges internally lamellate, the tip a flattened unguis. Nostrils 

 elliptical, open, sub-basal. Head of moderate size; neck long or of mode- 

 rate length, slender; body full; legs generally short, stout, with little of the 

 tibia bare; tarsus scutellate; toes four, first small; anterior three palmate. 

 Claws moderate, arched, compressed, obtuse. Plumage very full, dense, 



