270 AVES. 



Fam. Gypogeranidae. Slender body, with long neck, long wings and tail, 

 and much elongated metatarsus. Beak with extended cere, laterally compressed 

 and strongly curved. Grypogeranus serpentarius 111., Secretary bird. Flies 

 badly, but runs well ; preys on snakes in Africa. 



II. RATITJE. 



Birds incapable of flight, without sternal keel, and without firm 

 remiges or rectrices. 



Order 1. CURSORES ; 



Ratitce of considerable body size, with three-toed or exceptionally 

 with two-toed cursorial feet. 



The Ostriches, which are the largest of living birds, possess a broad 

 and flat, deeply-slit beak with a blunt point, a relatively small, in 

 part naked, head, a long, slightly feathered neck and long powerful 

 cursorial legs. Besides the reduction of the wing-bones, there are 

 other peculiarities of skeletal structure which characterise these birds 

 as being exclusively cursorial. Almost all the bones are heavy and 

 massive, with much reduced pneumaticity. The sternum has the 

 form of a broad, slightly arched plate, without any trace of a keel. 

 The clavicle also is undeveloped, and the unciriate processes of the 

 ribs are rudimentary or entirely absent. The plumage covers the 

 body with tolerable uniformity, except that there are naked places 

 on the head, the neck, the extremities, and the abdomen ; but does 

 not present any regular arrangement of pterylce ; it approximates in 

 its special structure to the hairy covering of Mammalia (Cassowary). 

 While the down is much reduced, the contour-feathers have a more 

 down-like appearance on account of their flexible shaft and lax vane, 

 or they may be stiff and hair-like with setiform barbs, or sometimes, 

 as in the wings of the Cassowary, they are spine-like. 



Fam. Struthionidae. Two-toed Ostriches. With naked head and neck, 

 pubic symphysis and long, completely naked, two-toed legs. They inhabit the 

 plains and deserts of Africa. They live in companies, and are polygamous. 

 Strutliio camelus L., Ostrich. 



Fam. Rheidae. Three-toed Ostriches. With partially feathered head and 

 neck, and three-toed feet. They inhabit America. Rhea americana Lam., 

 Khea. 



Fam. Casuariidae With high, almost compressed beak, and usually a helmet- 

 shaped, bony knob on the head, with short neck and three-toed legs. Dromeens 

 Forte Hollandice Gray. Emeu, Australia ; Casuarius galeatus Vieill., Cassowary, 

 New Guinea [Ceram]. 



