PONGO 197 
of the face, and broadens greatly at the canines. The molar series 
are large, the premolars only slightly smaller than the molars. There 
are three other skulls from Batangtu of old males, all smaller than 
No. 141, and varying in size, No. 23 being the smallest. All these 
possess crests, while the shape of the braincase varies in each, and all 
are different from No. 141. In three there is a considerable slope of 
the facial region, No. 24 having the least, but No. 23 has the greatest 
of all. There is much difference in the shape and size of the orbits, 
No. 41 being decidedly an elliptical oval, two of the others more 
rounded but varying in degree, the smallest skull, No. 23, having very 
large orbits higher than wide, being also more of an elliptical oval like 
those of No. 41. The rostrum of each of these four skulls also shows 
much variation in both length and width. In fact these crania are 
more remarkable for the way in which they vary from each other than 
for any similarity which they exhibit. 
The following dimensions are from a skull of the Dadap District: 
Measurements. Skull. Total length, 212; occipito-nasal length, 
168 ; intertemporal width, 75; breadth of braincase, 103; Hensel, 174; 
zygomatic width, 174; extreme breadth of orbits 127; width of rostrum 
at canines, 73; palatal length, 94.8; length of upper canines, 32.8; 
length of upper molar series, 55.8; length of mandible, 182: length of 
lower molar series, 65.3. No. 169 Selenka Collection, Munich Museum. 
As is the case with all the skulls of the various forms recognized 
by Selenka in his Collection, the great majority are those of immature 
animals, even very young individuals, and with a few old females. 
So it was possible to procure only four old adult males of dadappensis, 
and two of genepaiensis. Even with this small number the variations 
exhibited by these skulls were extraordinary. Two of dadappensis, 
Nos. 169 and 183, are nearest in general appearance, but even they 
show considerable differences. No. 169 is slightly the larger, with a 
larger and more rounded braincase, round orbits, instead of oval as in 
the other, and a longer rostrum. Both have bony crests, that of No. 
183 being the longer, but that of 169 the higher. The low ridges from 
the outside of the orbits recede over the skull very differently, that of 
‘169 not joining the bony crest until beyond the frontal, and enclosing 
a large part of that bone between them, while on 183 these ridges meet 
the crest midway of the frontal and enclose a very small portion of 
that bone. The fourth skull, No. 165, is altogether a different object. 
It has no bony crest, the braincase rises considerably above the orbital 
ridges, and is rounded, and the low ridges from the orbits go back- 
