The American Journal of Science

actinium åkermanite Aletomeryx ant.-post Antilocapra Archæotherium atoms basalt beds calcite calcium canine carbon clavus clavus cones crassum Cretaceous crystals curve cusps Dakota dependent process deposits diameter dike Dinohyus Entelodon feet feldspar flow foramen formation fossa fossil genus Geology glass glenoid cavity heel Holotype hypocone igneous indices intrusives island JOUR jugal Lake Lake Timiskaming lavas Leidy leucite limestone Lipari lower jaw magnetite Marsh melanterite mental tubercles mineral Miocene molars mountains obsidian Oligocene olivine One-fifth nat orbit Oreodon orogenies oxide oxygen P₁ Paleozoic Pecos Pelonax phenocrysts photograph Pirsson planes plate posterior premolar present radium ramus ratio relative rhombohedron rhyolites River rock San Andreas sandstone SCI.-FOURTH SERIES shales side skull slender species specimen structure surface tanks teeth thickness Timiskaming tion tooth transverse U. S. Geol unconformity upper uranium Valley volcano wave lengths width Yeso