BIRDS. 



345^ 



Fig. 337- Restoration of Hesperoi-nis^ after Marsh. 



ORDER IV. EURHIPIDUR^. 



Toothless birds with pygostyle and saddle-shaped centra tcp 

 the presacral vertebrae. The rami of the lower jaw are firmly 

 united. To this order belong all living and many extinct birds. 



Sub-Order i. Drom^ognathi. 



Eurhipidurine birds with dromaeognathous palate ; ischium and iliumi 

 not united behind; sternum either ratite or carinate ; wings rudimentary or- 

 of no use in flight. 



Section I. STRUTHIONES. Large ratite birds with elongate hind 

 Ics and neck ; bill broad at base ; mouth deeply split ; toes three or two. 

 Restricted to the southern hemisphere. The Struthionid^, containing^ 

 the sino-le species Struthio camelus, the ostrich of Africa, has but two toes. 

 The South American Rheid/E, which have three toes, contain the nandu. 



