The cranial region is comparatively small. The supra-orbital ridges, in which the eye-brows are set, form, from their prominence, a marked feature of the face. They overhang the eyes, causing them to appear very much sunk in the skull. The neck is short, the chest and shoulders wide, thickly haired and suggestive of great strength. The arms are much longer than the fore-arms, and the feet, which have no in-step, exceed the hands in length, and are much broader than in other genera of the _Simiidæ_. The heel, which in the Orangs is small, is in the Gorilla strongly developed, on which account it can easily stand erect. Its opposable great-toe is large and flattened, and has a wide nail; while the lower joints of the second, third, and fourth toes--which are also short and thick--are united by a web. The arms, on which the hair converges on both sides of the joint towards the elbow, are so long as to reach down to the middle {182}of the leg when the Gorilla stands erect. The thumb is short and thick, and is tipped with a broad nail. The hand is broad, thickly haired on the back, and wrinkled from the wrist to the fingers. The fur of the Gorilla consists of long, thick, straight, or stiffly curved bristles, beneath which is a shorter curled woolly hair, or under-fur. The skull of the adult male has very protruding jaws, and enormous supra-orbital ridges. The cheek-bones are broad; the temporal muscles meet along the top of the cranium, and have enormous bony crests for their attachment. The same is the case on the back of the head for the powerful neck-muscles. The true form of the skull is obscured by these great ridges and by the extent to which the face protrudes. The brain-case is better shaped internally than appears externally. The orbits have the same form as in Man. The canine teeth are enormously developed. The upper molars are four-cusped, and have the oblique ridge, already often referred to, from the front inner to the hind outer cusp, the posterior of the three being much larger than the other two, a character distinguishing its jaw from that of Man and the Chimpanzees. The anterior lower molars have five cusps, three on the outer side and two on the inner, as in Man. The lower jaw has no true chin, and its symphysis is very long and quite different from what is seen in the human symphysis. The opening for the passage of the spinal cord is situated in the posterior third of the base of the skull, and not, as in Man, nearly in the centre. The vertebræ of the neck, back, and loins number the same--seventeen--as in Man; but there are thirteen parts of ribs instead of twelve. The neck-vertebræ have long spines which contribute to the thickness of the neck. The curvature, characteristic of {183}Man, in the lumbar region of the vertebral column of the young Gorilla, is more developed than in the Chimpanzee, and in both are earlier developed than in Man. (_Symington._)