My dear Sir—

I take the liberty of sending you the first lower molar of a Horse, the skull of which (almost entire) I found fossil in a deep deposit in the Valley of Quito, 10000 ft. above the sea. The remains of the Horse, as I mentioned in a former letter, were accompanied by relics of a Mastodon, Deer, Llama, Auchenia &c.¹ I am curious to know the species of the Horse; how it differs from other sp. of Horse found elsewhere in South America and lately by Prof Owen in the tertiary of Mexico.² The entire specimen (and I believe this is the first equine skull found in South America) would be a better guide; but perhaps this tooth will show its affinities. If you have not the time to examine it, will you please send it to Prof. Owen.

I am with high respect | Your obedient Servant | James Orton.

PS. My book on “The Andes and the Amazon” will be out in November, when I shall have the honor of sending you a copy.³