ANSERINE. 
145 
slender ; the head rather small, oblong, compressed, and 
arched above. Bill stout, short or moderate, much higher 
than broad at the base, gradually depressed toward the 
end, of nearly equal breadth or narrowed, with large con- 
vex unguis. Upper mandible internally concave, with a 
medial tuberculate ridge, one or two series of tubercles 
on each side, then a series of flattened lamellae, and along 
the margin numerous lamellae, often enlarged at the end ; 
tongue fleshy, thick, margined with pointed papillae or 
fibres ; oesophagus long, narrow, a little enlarged below ; 
stomach a transversely elliptical gizzard, of which the 
lateral muscles are extremely thick, the tendons large, 
the epithelium with two circular, somewhat concave, thick 
grinding plates ; intestine long, rather narrow ; coeca long, 
narrow at the base, then enlarged, and nearly cylindrical. 
Trachea nearly uniform, with the inferior larynx simple 
and compressed. Nostrils small or moderate, submedial, 
oblong. Eyes small. Aperture of ear rather small. Legs 
placed considerably forward, very strong, generally of 
moderate length ; tibia bare for a short space ; tarsus 
moderately compressed ; toes four, the first very small, 
and free ; the anterior rather long, the outer little shorter 
than the third ; the interdigital membrane full ; claws 
short, arched, obtuse. Plumage rather full, close, and 
firm, unless on the head and neck, where it is soft and 
blended ; wings very long and broad ; primaries decurved, 
the second and third longest, the first little shorter ; tail 
short, rounded, of from sixteen to twenty-four feathers. 
The Anserinse inhabit chiefly the Arctic and Antarctic 
regions in summer, migrating in autumn toward the 
Equator. They are all gregarious, fly in lines when jour- 
neying, have a strong and rapid flight, w r alk slowly, swim 
with ease, but never dive in quest of their food, which 
consists entirely of vegetable substances. Although they 
feed chiefly on land, or in marshy places, they also, when 
swimming in shallow water, pull up the submersed parts 
K 
