THE TEETH OF MAMMALS 181 



ally assume the bicuspid form, but the cusps are 

 large, long, and sharp. The true molars have 

 four prominent sharp-pointed cusps with an an- 

 terior and posterior basal ridge. They progres- 

 sively increase in size from the first to the third 

 in all Baboons. The crowns of the lower molars 

 are narrower and longer than the upper, and the 

 last has a fifth lobe or tubercle. The first lower 

 premolar is bicuspid or unicuspid, but the second 

 is quadricuspid. In the long-tailed monkeys, the 

 upper molars have four tubercles, and the lowers 

 five. In some Catyrrhine monkeys the curved 

 form of the arch begins to appear. In some the 

 teeth have long, sharp cusps, indicating an insec- 

 tivorous diet. In most of the higher species they 

 are tuberculate, as in man, indicating a mixed diet. 

 The deciduous set are the same as those of man 

 and succeed each other similarly, but with some 

 variation as to the time of the eruption of the 

 teeth. 



