AZ MAMMALIA OF INDIA. 
under similar circumstances and did not recover till his rival (a Siamang, 
fH. syndactylus) was removed. 
No. 3. HYLOBATES SYNDACTYLUS. 
The Siamang. 
Hasitat.—Tenasserim Province, Sumatra, Malayan Peninsula. 
DeEscRIPTION.—A more robust and thick-set animal than the two 
last ; deep, woolly, black fur; no white supercilium nor white round the 
face. ‘The skull is distinguished from the skull of the other Gibbons, 
according to Dr. Anderson, by the greater forward projection of the 
supraorbital ridges, and by its much deeper face, and the occipital 
region more abruptly truncated than in the other species. The index 
and middle toes of the foot are united to the last phalange. 
S1zE.—About three feet. 
This Gibbon is included in the Indian group on the authority of 
Helfer, who stated it to be found in the southern parts of the Tenasserim 
province. Blyth mentions another distinguishing characteristic—it is 
not only larger than the other Gibbons, but it possesses an inflatable 
laryngeal sac. Its arms are immense—five feet across in an adult of 
three feet high. 
The other species of this genus inhabiting adjacent and other 
countries are /Z. pileatus and HZ. leucogenys in Siam; HW. deuciscus, Java ; 
ff, Mulleri and H. concolor, Borneo. 
GENUS PRESBYTES—CUVIER’S GENUS SEMNOPITHECUS. 
These monkeys are characterised by their slender bodies and long 
limbs and tails. Jerdon says the-Germans call them Slim-apes. Other 
striking peculiarities are the absence of cheek pouches, which, if pre- 
sent, are but rudimentary. Then they differ from the true monkeys 
(Cercopithecus) by the form of the last molar tooth in the lower jaw, 
which has five tubercles instead of four ; and, finally, they are to be 
distinguished by the peculiar structure of the stomach, which is singularly 
complicated, almost as much so as in the case of Ruminants, which 
have four divisions. The stomach of this genus of monkey consists of 
three divisions: rst, a simple cardiac pouch with smooth parietes ; 
2nd, a wide sacculated middle portion; 3rd, a narrow elongated 
canal, sacculated at first, and of simple structure towards the termination. 
Cuvier from this supposes it to be more herbivorous than other genera, 
and considers this conclusion justified by the blunter tubercles of the 
molars and greater length of intestines and ccecum, all of which point 
