101 
lcnp;th from length of length of length of length of 
vertex to (inus. 
arm. 
forearm. 
thigh. 
June 14. 1886. 
27,5 cm. 
14 
17 
12 
14 
May 5. 1887. 
40,5 
17,1 
21 
14 
16 
November 1. 1887. 
41,75 
19,2 
22,5 
15,5 
17 
In the first place the forearm is therefore increasing in length and 
is the principal cause of the enormous length of the arms in the full 
grown individual. 
From my material collected in India and from some measurements 
of skeletons in the Leyden Museum and in the collections of the Royal 
Zoological Society of Amsterdam , the same conclusion may be derived. 
In Hylobates syndactylus that in other respects is very different from 
the other species of Hylobates, this difference is not the least, as 
may be seen from some of my measurements. 
Hylobates syndactylus. 
Length from atlas 
to apex coccygis. 
Humerus. 
Radius. 
Femur. 
Tibia. 
Specimen Amsterdam. 
24,5 
17,2 
18,1 
13,4 
11,7 
Specimen Amsterdam. 
Specimen Amsterdam. 
(189). 
40 
39,9 
26,5 
27 
28,2 
30 
20,5 
20,3 
17,8 
17,2 
Specimen Leyden. 
41 
29 
32,2 
22 
19 
Specimen Amsterdam. 
(167) in spirit. 
Specimen Amsterdam. 
(121) in spirit. 
from vertex to apex 
coccygis. 
28,5 
53 
11 
28 
11 
29 
8,25 
19,5 
8,25 
18,75 
Hylobates leuciscus. 
from atlas to apex 
coccygis. 
Specimen Leyden. 
18 
13,4 
13,5 
10,6 
10,2 
Specimen Leyden. 
28,2 
18,4 
22,1 
15,6 
13,2 
Specimen Amsterdam. 
30,5 
22,6 
26,2 
19,8 
17,5 
Specimen Leyden. 
31,1 
22 
26 
20,5 
18,4 
Semnopithecus. 
Semnopithecus melalophus Raffles. 
(Sem. ferruginous, Schlegel). 
Sumatra: near Singkarah; ad 9- (110) ad. 'cT (HI). Kotta Sani near 
Solok; young ^ (166), a skeleton 9 (119) and a skull Ç 
