XI. Description of some species of the extinct genus nesodon, with remarks on the primary group (toxodontia) of hoofed quadrupeds, to which that genus is referable

The application of part of the Government Grant, allotted to procuring drawings of rare and nondescript fossil remains, has furnished the requisite illustrations of the following Memoir on some extinct Herbivorous animals, which indicate a primary group of the Ungulata, distinct from and probably equivalent, to one of the great divisions called Proboscidia, Artiodactyla, and Perissodactyla. Genus Nesodon*, O. The genus so called, from most of the enamel-folds penetrating the crown of the molars being, when exposed by use, of an insular form, was founded by me in 1846, on portions of an upper and lower jaw, with teeth, transmitted by Captain Sulivan, R. N., from the S. W. coast of Patagonia.