Allowing for the mistake in latitude, the King's Islands are evidently the same as those found on some old charts, about the nineteenth and twentieth degrees of north latitude, under the names of _La Mesa_, _Los Mayos_, and _La Disgraciada_; which Capt. Dixon, as well as La Perouse, sought for in vain in the longitude assigned to them. They appear to have been introduced into the {109} English and French charts from that found in the galleon taken by Commodore Anson, and of which a copy is given in the account of his voyage. Cook, or Lieutenant Roberts, the compiler of the charts to his third voyage, retained them; and La Perouse was the first to erase them from the map. There can, indeed, be little doubt of their identity with the Sandwich Islands. But although Cook was not actually the first European who had visited those islands, to him rightly belongs all the glory of their discovery. Forgotten by the Spaniards, misplaced on the chart a thousand miles too far to the eastward, and unapproached for 240 years, their existence utterly unknown and unsuspected, Cook was, to all intents and purposes, their real discoverer. C. E. BAGOT. Dublin. * * * * * MEGATHERIUM AMERICANUM. (Vol. vii., p. 590.) Is not the cast of a skeleton in the British Museum, recently alluded to by A FOREIGN SURGEON, and which is labelled _Megatherium Americanum_ Blume., better known to English naturalists by its more correct designation of _Mylodon robustus_ Owen; and if so, why is the proper appellation not painted on the label? If that had been done, _A Foreign Surgeon_ would not have fallen into the error of confounding the remains of two distinctly different animals. Might I beg leave to add, for the information of your correspondent, that no British naturalist "of any mark or likelihood," has ever assumed that (though undoubtedly sloths) either the _Mylodon_, _Scelidotherium_, or _Megatherium_, were climbers. Indeed, the whole osseous structure of those animals proves that they were formed to uprend the trees that gave them sustenance. By no other hypothesis can we intelligibly account for the immense expanse of pelvis, the great bulk of hind-legs, the solid tail, the massive anterior limbs furnished with such powerful claws, and the extraordinary large spinal chord--all these the characteristic features of the _Mylodon_. Whether there were palms or not at the period of the telluric formation, I cannot undertake to say; but as A FOREIGN SURGEON assumes that a palm is an exogenous tree (!), I am induced to suspect that his acquaintance with geology may be equally as limited as his knowledge of botany. Besides, what can he mean by speaking of a sloth "the size of a large bear?" Why, the _Mylodon_ must have been larger than a rhinoceros or hippopotamus. The veriest tyro in natural history would see that at the first glance of the massive skeleton.