268 ZOOLOGY. 
Order 6. Sirenia, — General Characters of Sirenians.— 
This small group is represented by the sea-cow or manatee 
of Florida. The lower jaw is unlike that of whales, being 
much as in the cow or horse, while the teeth are well devel- 
oped, both incisors and molars, the latter with flattened or 
ridged crowns, adapted for the trituration of vegetable 
