412 ZOOLOGY 



industry in South Africa and to a certain extent in America, 

 on account of the plumes which are extensively used as orna- 

 ments. Besides the types mentioned there are a number of 

 extinct forms belonging to this division, some of which have 

 become extinct in recent time. Mpyornis is one of these, 

 formerly a native of Madagascar, where remnants of its eggs 

 have been discovered showing that its volume was about six 



FIG. 212. 



FIG. 212. Wood Duck (Aix sponsa). Photographed by Dr. J. W. Folsom. 



times that of the ostrich egg, i.e., having a capacity of about 

 two gallons. 



Division II. Carinatce (with a keel). Birds with the keeled 

 breast bone, the wings, and the other organs of flight usually 

 well developed. Barbs of the feathers have barbules. All the 

 modern flying birds are embraced in this subclass. 



The further subdivisions of the Carinatse, as given in the 

 recent classifications, based upon internal structure, are entirely 

 unsuited for beginners. An older arrangement of the prin- 

 cipal orders, based upon habits and certain superficial features, 

 is presented below for the convenience of the student. It 



