^{page no 342 note *} The crania of the adult male and younger chimpanzee are in the Anatomical Museum of the University; that of the adult female is in the possession of Dr John Alexander Smith. In the adult and apparently aged chimpanzee crania the sutures were all ossified. In the younger animal, although all the permanent teeth had erupted, yet the sutures of the cranial vault were unossified, and the basi-cranial synchondrosis, though ossified, had its position marked by a transverse bony ridge.

^{page no 344 note *} Although it would appear from an examination of a considerable number of crania of old-world monkeys that the rule is in them for a tongue-shaped process of the temporal to articulate with the frontal, and consequently to cut off the ali-sphenoid from the parietal, yet several crania have been noted in which the ali-sphenoid and parietal had a well-marked articulation with each other. Some of these skulls had unfortunately not been named, and it was difficult exactly to identify them; but in a skull of Semnopithecus entellus and in one of Macacus cynomolgus, the ali-sphenoid articulated on both sides with the parietal; and though in two crania of Cynocephali the temporal and frontal articulated, yet in a third, whilst 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 articulated 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, pl. 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 diagnostic characters between the crania of men and monkeys.

^{page no 345 note *} 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.

^{page no 346 note *} In the crania of the orangs and of the gibbons an arrangement of the upper end of the premaxillae, closely similar to that described in the chimpanzee, was seen. In only one skull of the orang did a linear process of the premaxilla pass upwards for of an inch between the nasal and superior maxilla. Hence the intercalated triangular plate at the upper end of the premaxilla of the gorilla is valuable as a diagnostic character to distinguish the skull of that animal not only from the skull of the chimpanzee, but from those of the other anthropoid apes. In the mode of termination, however, of its premaxillse superiorly the gorilla closely corresponds with the arrangement seen in the skulls of many of the tailed apes, e. g., Cynocephalus, Semnopithecus, Cercopithecus.

^{page no 347 note *} Dr Wyman states that in the crania he has examined there are indications of a suture separating the lower part of the nasals from the inter-orbital part, the latter of which he looks upon as an additional osseous element intercalated between the frontals. May not such a groove as the one described in the text have been regarded as a suture?

^{page no 347 note †} So far as could be judged from the skull of the younger chimpanzee, in that animal the ethmoid did not articulate with the lachrymal by its anterio margin, the superior maxillary and frontal having processes intercalated between. In the orangs and gibbons, again, the ossa plana were quadrilateral plates, and articulated by their anterior margins with the posterior margins of the lachrymal bones.

^{page no 348 note *} In the formation of the diastema in the crania of some apes, it would appear as if the premaxilla and the canine portion of the superior maxillary bone participated in an equal degree, for the maxillo-premaxillary suture was mostly situated, in the adult jaw, about midway between the canine and lateral incisor teeth. In others, however, e. g., several cynocephali, the suture was placed much nearer the canine tooth, and the interval was occasioned by an increased growth of the premaxilla between that suture and the socket for the lateral incisor.