616 ON A NEW MONKEY FROM SUMATRA. [DeC. 6, 



(in which the snout is proportionally longer) to the centre of the 

 foramen incisivum. 



Intertemporal constriction strong ; it equals the distance from the 

 foramen magnum to the centre or hinder edge of ^ 



The nasals are slender and straight, or even somewhat concave ; 

 ahove them the interorbital space is sunk inwards. 



The hullcB are low, almost flattened in the female, but rather 

 more elevated in the old male. 



The canines in the male are particularly long. 



The lower jaw is almost uniformly high throughout its length 

 from P:^ to m£*. 



The occipital is strongly rounded behind, and does not show a 

 trace of any transverse crest. 



The orbits are wide, with a distinct angle above on the outer side ; 

 their height is less than their breadth. 



In the young one the peculiarities of the skull are still but little 

 prominent. The bulla are proportionally more swollen than in the 

 old ones. 



Habits. — These Monkeys were only met with by Herr Iversen in 

 the Langkat district, and were not observed in Deli. They were 

 fairly numerous on several of the estates, especially at Glen Bervie 

 and Bekri. Their haunts were in the highest trees, and they never 

 descended of their own accord to the ground or visited the rice- 

 fields. Herr Iversen saw, however, one wounded individual take to 

 flight on the ground. They always live in companies, and inhabit 

 the dry spots in the thickest parts of the forests. They appear 

 to be non-migratory, and may be met with at all times of the year 

 in almost the same parts of the forest. They hardly ever visited the 

 more open places, but kept to the highest tree-tops, where they 

 moved about with the greatest ease, and made the most astonishing 

 leaps through the branches. They were on the whole excessively 

 shy ; if they found themselves noticed, they endeavoured at once to 

 hide themselves, and the mothers would leave their young sitting 

 on the branches whilst they themselves sought shelter in the tree- 

 tops. When hunted, they all took to flight in the same direction, 

 so that the companies were not dispersed. 



The companies appeared to consist chiefly of full-grown indivi- 

 duals, and young ones were but seldom seen. An occasional half- 

 grown individual, however, might be noticed following the old ones ; 

 babies were not often seen, but these are, on the whole, more difficult 

 to observe, as they are carried by the mother under her belly. 



The young one brought home was noticed through the mother 

 deserting it, after which it began to shriek. They have a very 

 penetrating cry, which they generally utter in chorus after one has 

 given the note. In the individuals which have been examined no 

 foetus has ever been found. Possibly the pregnant females and the 

 younger ones hide themselves more closely. 



They were seen in activity only in the daytime, and were not heard 

 to cry at night. They lived, it appeared, only on fruits. In their 

 stomachs was chiefly found the soft pulp of a fruit belonging 



