The principal points in the geography of Asia, as given by Ptolemy, respect the coasts of India, the route to the Seres, and the Caspian sea. His delineation of India is equally erroneous with his delineation of the British Isles: according to him, it stretches in a right line from west to east, a little to the south of a line drawn between the Ganges and the Indus. He possessed, however, information respecting places in the farther peninsula of India, the locality of several of which, by comparing his names with the Sanscrit, may be traced with considerable certainty. He assigns to the island of Ceylon a very erroneous locality, arising from his error respecting the form of India, and likewise an extent far exceeding the truth. He is the first author, however, who mentions the seven mouths of the Ganges. The route to the Seres, which he describes, has been already noticed: it is remarkable that the latitude which he assigns to his Sera metropolis, is within little more than a degree of the latitude of Pekin, which, in the opinion of Dr. Vincent, is one of the most illustrious approximations to truth that ancient geography affords. His description of Arabia is, on the whole, accurate; he has, however, greatly diminished the extent of the Arabian Gulf, and by at the same time increasing the size of the Persian, he has necessarily given an erroneous form to this part of Asia. The ancient opinion of Herodotus, that the Caspian was a sea by itself, unconnected with any other, which was overlooked or disbelieved by Strabo, Arrian, &c. was adopted by Ptolemy, but he erroneously describes it as if its greatest length was from east to west. The peninsula to which he gives the name of the Golden Chersonesus, and which is probably Malacca, he describes as stretching from north to south: to the east of it he places a great bay, and in the most distant part of it the station of Catigara. Beyond this, he asserts that the earth is utterly unknown, and that the land bends from this to the west, till it joins the promontory of Prasum in Africa, at which place this quarter of the world terminated to the south. Hence it appears that he did not admit a communication between the Indian and Atlantic oceans, and that he believed the Erythrean sea to be a vast basin, entirely enclosed by the land.