PHCENICOPTERID^, FLAMINGOES. 277 



than a lever for increase of motion. This shortening is generally so marked that 

 the knee is entirelj^ withdrawn within the general skin of the body — a special 

 characteristic of swimming birds ; and in the best swimmers, the whole limb is thus 

 bm-ied 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 bill 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 Spheniscida; , or penguins. 



Order LAMELLIKOSTEES. 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 fieshy, 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 shoit. Tail generally short and 

 many-feathered. Oesophagus narrower than in the lower flesh-eating orders, 

 usually with a more or less specially formed crop ; gizzard strongly muscular ; 

 intestines and their ca3ca long ; cloaca capacious. Legs near centre of equilibrium ; 

 position of body in walking horizontal or nearly so. Reproduction prfficocial. 

 Sexual habit frequently polygamous. Diet various, commonl}^ rather vegetarian 

 than animal. There are two remarkably diverse families of lamellirostral birds. 



Family PHCENICOPTERID^. Flamingoes. 



Bill very large and thick, entirely invested with membrane (without tlie horny 

 terminal nail of the Anatidce) which extends around the eyes, and abruptly bent 

 downward at the middle. Legs and neck exceedingly long. Tibiffi 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 niceljr 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 afBnity. 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 abrupit bend brings the upper surface 

 in contact with the ground in the act of feeding. The nest is a heap of earth 



