The American Journal of Science, Band 2;Band 202

ant.-post appears approximately Arkansas armatum atoms bones Bull bullæ Camelops Canopus Cenozoic chemical classification cleavage Cretaceous culbertsonii density deposits diameter Diceratherium earth ectoloph Eocene Eporeodon equator evidence fauna feet feldspars foramen formation fossil genus geologic gravity groups Holotype Hyracodon igneous rocks incisor isostasy isostatic John Day River JOUR land area Leidy length level surfaces lower mammals Marsh mass material Meadow Valley Menoceras Merycoidodon metaloph Metamynodon middle John Day mineral Miocene Mississippian molar series molars Muddy Valley nasals Oklahoma Oligocene Oreodon Osborn Ouachita Mountains Ouachita region Paleocene Paleozoic Pennsylvanian pistillate porphyritic posterior premolar series premolars present rhinoceroses River sagittal crest sandstone SCI.-FIFTH SERIES sediments shale shows skull species specimens sphere spikes structure subsp superior premolars Survey teeth Tertiary Tetrameryx Texas thick tion tooth transverse tridactylus U. S. Geol Upper Oligocene valentinite vertebrate vertical Width