Description of a Gibbon. 35 



projecting, extending nearly to the mental foramina when 

 the jaws are closed ; their anterior edges worn bj the 

 lower canines. No lateral or grinding motion of the jaws 

 can be effected by bringing them together, in consequence 

 of the length of these upper canines. The two next are 

 false molars. All the molars small. The four inferior 

 incisors are small; of an uniform size, and have sharp, 

 cutting edges. The canines project upwards as far as 

 the alveolar processes of the upper jaw. The first false 

 molai^s are worn away externally by the upper canines, 

 and terminate in single points. 



There are twenty-five vertebra:;. The six lower cer- 

 vical are peculiar as to their transverse processes, which 

 do not extend as far as the articulating processes laterally, 

 and they also project downwards. The atlas is by much 

 the widest. The spinous processes are short, (as seen in 

 the second plate,) and do not bifurcate; and these pro- 

 cesses throughout the whole column; from the atlas to the 

 coccyx, form a perfectly straight line. Thirteen dorsal 

 vertebrae- The lumbar have some peculiarities. The 

 superior articulating processes project upwards, especially 

 the first, which temiinates in a very sharp point. The 

 transverse processes of the fourth and fiftli are large, flat, 

 and extend outwards. (See plate 1.) Only one bone to the 

 coccyx. The sacrum consists at present of but one piece, 

 though some faint traces remain of a former division of this 

 bone into three. The ribs are thirteen in number, very con- 

 vex. The chest capacious and round. The first and second 

 ribs are articulated to the manubrium of the sternum. The 

 five next to the second piece. Six false ribs, four of which 

 are floating. The sternum has three bones.- The t^'o 

 first receive the cartilaginous tenninations of the seven 

 superior ribs^ while the third, which is an inch in length, 

 is unconnected with the ribs, and has affixed to it, abroad, 

 ensiform appendix. 



