378 GENERAL ZOOLOGY 



forest regions. The eggs are laid in a deep depression in the 

 sand, or in a rough nest in the case of the cassowary. The 

 ostrich is the best known of the group, largely on account of 

 the beautiful wing and tail plumes, which have been used 

 for ornaments from very early times. Ostriches are now 

 raised for the sake of the plumes on "farms" in California 

 and South Africa. 



Diving Birds. The group Pygop'odes (Gr. pyge, "rump" ; 

 pous (pod-), "foot") includes various species of water birds 

 with webbed or lobed toes (Fig. 197). Their scientific name 

 refers to the fact that the legs are placed very far back, so 

 that when standing, an erect position is assumed. The tail is 

 very short. The beak is sharp and pointed and fitted for cap- 

 turing fishes, which constitute a large part of their food. 

 They are expert divers and can swim under water with only 

 the tip of the bill exposed. The nest is generally nothing 

 more than a floating mass of decaying vegetation, attached 

 perhaps to some reeds in shallow water. Our northern lakes 

 and ponds are often visited by the loon, a characteristic 

 diving bird. 



Gulls and Terns. The group Longipen'nes (Lat. longus, 

 "long" ; penna, "feather") includes long- winged water birds 

 with sharply pointed or hooked beaks* The colors are usually 

 gray above and lighter below. The three front toes are con- 

 nected by a web (Fig. 197). These birds are strong and 

 graceful fliers, and spend much of their time on the wing. 

 All the members of the group are gregarious, occupying 

 nesting sites on sandy beaches, in marshes, or on rocky 

 shores. They obtain the greater part of their food from 

 the ocean and lakes, and are useful as scavengers. Terns 

 (Fig. 198) may be distinguished from gulls by their usually 

 deeply forked tail and straight bill. Gulls are generally 

 pelagic, and they often follow ships for the sake of the 

 refuse thrown overboard ; terns frequent the shores of 



