VERTEBRATA I MAMMALIA. 



is the true organ of digestion, corresponding to the simple 

 stomach of mammals in general. 



The Even-toed ungulates, or Artiodactyls, have the 

 molars each with two double crescent-like folds, whose 

 convex surfaces are inside ; and the canines of the lower 

 jaw except in Camelidse are in the same row with the 

 incisors, and closely resemble them. 



Of all the Ungulates, few, and perhaps none, are more 

 remarkable than the Camels and the Llamas, which con- 



FIG. 103. 



One-humped Camel, Camelus dromedarius, Linnseus. 



stitute the family of Camelidse. The true Camels (Came- 

 lus} have the toes united below nearly to the point by a 

 common sole, and the back furnished with humps of fat. 

 They have canine teeth in both jaws those of the lower 

 jaw being specialized and different from the incisors two 

 pointed teeth in the place of incisors in the upper jaw, 

 six incisors in the lower jaw, and eighteen to twenty 

 molars. Camels are natives of Central and Southwestern 



