distinguished by small external ears; a large double throat-sac; anterior extremities greatly developed, the hands reaching to the ankle; hinder hands very long and narrow, thumbs small, and often destitute of the nail and nail-joint; ribs twelve pairs; canines in adult male very large; no cheek pouches, no callosities on the rump; and no tail.
The great islands of the Indian Archipelago are the homes of this genus, particularly Borneo and Sumatra. Eminent zoologists consider that the specimens received from these two islands are of two species, distinguished as Pithecus Wurmbii (Geoff.), the Bornean Orang, and P. Abelli (Clark), that from Sumatra; the principal difference consisting in enormous callous excrescences on the temples and cheeks of the adult male of the former species, which seem to be wanting in the latter. Both attain to a great size and stature: a specimen has been recently obtained in Borneo, measuring five feet nine inches in height; while the individual of whose capture in Sumatra, Dr. Abel has given so interesting a narrative, is said to have attained the gigantic stature of seven feet six inches. The colour of the hair in both species is reddish brown, varying in individuals from a sandy hue to that of dark mahogany; it is copious on the sides, but scanty on most other parts. The disproportionate size and length of the arms, when compared with the legs, is a very marked character, and associated with the long and hooked character of the hands, shews that the Orang is more exclusively arboreal than the Chimpanzee. In young specimens the skull is large in the upper part, and the fore-
