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POrULAK SCIENCE REVIEW. 
The Gibbons (or long-armed apes) form the genus Hylohates, 
containing several distinct species, the largest and most interest- 
ing of which is called the Siamang. 
Fig. 2. 
The Orang {Simia). 
In external appearance the Gibbons more nearly resemble 
the Orang than the African Troglodytes, on account of the length 
of the arms, which is even greater than in Simla. They are, 
however, much more active in their habits, though generally 
gentle in disposition. The power of voice possessed by some 
