PAPIO CTA’OCEPHALUS. 
73 
After maturity has been reached and has lasted for a few years, other changes ensue 
which still further modify the skull. 
The following characters are found associated together in a fully adult skull:— 
[a) the posterior border of the last molar lies n ell before the anterior malar root of 
the zygomatic arch; (5) a long triangular postdental tract is developed behind the last 
molar; {c) the basioccipital suture has begun to disappear, i. e. union of the two bones 
has taken place more or less; {d) the temporal ridges unite on the sagittal suture or 
anterior to it. 
The skulls in the accompanying Tables which manifest the above characters 
are those from Osi-Tana, Moschi, Ukami, Zomba, Lamu, Fort Johnston, and 
Langenberg. 
In skulls not fully adult the following are the characters:— {a) the posterior border 
of the last molar lies behind the anterior root of the zygomatic arch; {h) a very short 
triangular upwardly sloping tract is developed behind the last molar; (c) the basi¬ 
occipital suture has not united; {d) the temporal ridges in some are apart even on 
the occipital. 
In still younger skulls the following are the characters:— [a) the posterior border 
of the last molar is much behind the anterior root of the zygomatic arch; [h) no post¬ 
dental area is present behind the last molar; (c) the basioccipital suture is quite 
intact; {d) the temporal ridges are far apart. 
The skulls of 9 males and 1 female, represented by skins, are dealt with in 
Table II., in which they have been arranged according to their size, which, however, 
does not imply that two animals of the same size are of the same age. The 
largest male skull is from Zomba, to the south of Lake Nyassa, and it measures 
204 mm. long. It is fully adult, as are also the skull from Lamu and the one 
from Fort Johnston; but between these and the Langenberg skull, which is also adult, 
some skulls not fully adult are interpolated, so that the Langenberg skull, being adult, is 
that of a distinctly smaller individual. Fortunately, its skin is preserved in the Berlin 
Museum, and I have been enabled to compare it with two skins from Mpapwe, a 
district only 110 kilom. to the west of Unguru, whence the type of P. lanqheldi was 
obtained, and with a skin from Perondo, about halfway between Mpapwe and 
Langenberg. I have, however, failed to find any characters by which to separate it 
from them. 
The skull from Ukami, one of the specimens upon which Matschie founded 
his P. Jamglieldi, although unsubstantiated by a skin, may, on account of its general 
characters and the locality whence it came, be accepted as specifically identical with 
the Lamu baboon, the skull of which Mr. Oldfield Thomas has kindly allowed me to 
figure (Plate XIL). It may therefore be included along with the four adults from 
Lamu, Langenberg, Fort Johnston, and Zomba. This skull from Ukami (Table III, 
L 
