345 
of Edinburgh^ Session 1864-65. 
In the young gorilla, the squamous part of the occipital bone 
curved upwards and forwards for more than one inch beyond the 
rudimentary occipital crest, and contributed therefore to the forma- 
tion of the posterior part of the vault of the skull. In the adult 
animal the whole of this part of the bone was overlaid with the 
bony growth met with at the junction of the sagittal and occipital 
crests. The angle formed by the junction of the two sides of the 
lambdoidal suture was well marked in the young gorilla. In the 
younger chimpanzee a small fontanelle bone existed at each of the 
two extremities of the sagittal suture,* the squamous part of ^the 
occipital bone scarcely extended above the rudimentary occipital 
crest, and the lambdoidal suture passed across the back of the head 
in a line approaching much more closely to the horizontal than in 
the gorilla. The basi-cranial synchondrosis was ossified in the adult 
animals, hut not in the young gorilla. The zygomatic arches and 
mastoid processes closely corresponded with the descriptions given 
by Professor Owen. In the adult male and young gorilla the eusta- 
chian process of the petrosal (marked e in Ovv^en’s figure, plate 
Ixiii.) was little more than a well-marked tubercle ; but in the adult 
female it was prolonged downwards for half an inch as a well-formed 
styliform process. 
the parietal ; and though in two crania of Cynocephali the temporal and 
frontal articulated, yet in a third, wAiilst they articulated on the right side, 
on the left the ali-sphenoid joined the parietal. In crania of the following 
American monkeys, — Ateles, Cebus, Hapale,— the parietal bone not only arti- 
culated with the ali-sphenoid, but with the protuberant malar bone. Various 
anatomists (Owen, Humphry, &c.) have referred to Negro and Australian crania 
in which the temporal and frontal articulated. Barnard Davis has also figured 
an Anglo-Saxon skull from Ozingell, Kent (Crania Britannica, pi. 38), in 
which the same arrangement occurred. From the number of human crania 
referred to in the text in which this articulation was seen, it may ‘apparently 
exist in the skulls of any race as an individual peculiarity. The triquetral 
bone, not unfrequently met with in the sphenoido-parietal suture by separating 
these bones from each other, may be regarded as an approximation to this 
arrangement. The occasional occurrence, therefore, of the articulation of the 
frontal with the squamous part of the temporal bone in human skulls, and 
the extent of variation the ali-sphenoidal articulation exhibits in the crania 
of apes, gives to this feature but little value in the discrimination of the diag- 
nostic characters between the crania of men and monkeys. 
Dr Traill and Professor Owen observed in each of the crania of three 
young chimpanzees, at the posterior end of the sagittal suture, an os triquetrum. 
2 z 
VOL. V. 
