PHENICOPTERIDA, FLAMINGOES. 20 
than a lever for increase of motion. This shortening is generally so marked that 
the knee is entirely withdrawn within the general skin of the body—a special 
characteristic of swimming birds; and in the best swimmers, the whole limb is thus 
buried almost to the heel-joint. Finally, the natatorial limb becomes a rudder as 
well as an oar, serving to steer the bird’s course through the water, as much as the 
tail guides flight through the air. This is accomplished by the backward set of the 
legs—they project so far posteriorly, in many cases, that in standing on land, the 
birds necessarily assume a nearly upright position. The wings, tail and Dill differ 
according to families, as noticed under the several heads, beyond, while the more 
important points of the osseous and digestive systems are similarly diversified. 
The Natatorial plan is primarily carried out in four different ways, affording as 
many orders. All of these, and all their families excepting one, are represented 
within our limits. The missing family is that of the Spheniscide, or penguins. 
Order LAMELLIROSTRES. Anserine Birds. 
Bill lamellate: that is, both mandibles furnished along their tomial edges with 
series of laminar or teeth-like projections, alternating and fitting within each other. 
Covering of bill membranous, wholly or in greatest part. Tongue fleshy, usually 
with horny tip, and serrate or papillate edges corresponding to the denticulations 
of the bill. Feet palmate; hallux elevated, free, simple or lobed (rarely absent). 
Wings never exceedingly long, rarely very short. Tail generally short and 
many-feathered. sophagus narrower than in the lower flesh-eating orders, 
usually with a more or less specially formed crop; gizzard strongly muscular ; 
intestines and their ececa long; cloaca capacious. Legs near centre of equilibrium ; 
position of body in walking horizontal or nearly so. Reproduction precocial. 
Sexual habit frequently polygamous. Diet various, commonly rather vegetarian 
than animal. There are two remarkably diverse families of lamellirostral birds. 
Family PHQANICOPTERIDZA:. Flamingoes. 
Bill very large and thick, entirely invested with membrane (without the horny 
terminal nail of the Anatide) which extends around the eyes, and abruptly bent 
downward at the middle. Legs and neck exceedingly long. Tibixw largely bare 
below ; tarsus broadly scutellate, much longer than the toes. Front toes completely 
webbed; hallux very small, or wanting. Wings moderately long, ample. 
This is a small but very peculiar group of about six species, inhabiting various 
warm parts of the world. The external characters are so nicely balanced between 
those of wading and swimming birds, that the flamingoes have been placed indiffer- 
ently in both groups; but nearly the whole organization corresponds essentially 
with that of the duck tribe, the grallatorial relationship, in form and habits, though 
so evident, being rather of analogy than of affinity. In length of legs and neck 
these birds exhibit even an exaggeration of the characters of cranes, storks and 
herons. The bill is unique in shape; its abrupt bend brings the upper surface 
in contact with the ground in the act of feeding. The nest is a heap of earth 
a 
