66 ELEMENTS OF ORNITHOLOGY. 
in South America by a smaller Bird, which is called the Rhea 
or American Ostrich (7?hea americana), of which there are really 
three species. Another large and bulky Bird, quite incapable 
of flight, is the Cassowary (Casuarius galeatus) of the Papuan 
Islands and North Australia. There are nine species of this 
genus, Another very similar Bird is the Emeu (Dromeus nove- 
hollandie) of Australia. There are two species of this genus. 
Before proceeding further it may be useful to the student 
to take stock a little of the forms we have referred to, and 

The Cassowary ( Casuarius galeatus), 
endeavour briefly to class them in a merely popular manner, 
referring to external appearance, or modes of life, only. It is 
useful for the beginner to be able to think of them in large 
groups (such as the groups which first suggested them- 
selves to naturalists), even though he will find that such 
groups have to be largely modified owing to more recent 
advances in science. It is thus, indeed, that he will be best 
enabled to appreciate the value of such advances. 
Starting with our most familiar Bird, the Fowl, we have 
v 
f 
