Bulletin of the United States Geological Survey, Volumes 28-31

Agnostus amber Amer angles appears Bathyuriscus beak belong Berendt Billings Cambrian fauna Cañon Carboniferous cephalothorax character Collection U. S. National convex deposits described diallage diameter diorite dorsal valve Emmons Eureka extinct facial suture feldspar figured Florissant Ford fossils front furrows gabbro gabbro-diorite genera genus Geol Geological Survey Gilberti glabella groove head Heer horizon hornblende Hyolithes hypersthene insects interior known Kutorgina L'Anse au Loup lateral length limestone Lingulella lobe Lower Meek Menge Mesozoic Middle Cambrian mineral myriapods narrow nearly Nevada Obolella occur Oeningen Olenellus Olenoides outer pair Paleozoic Paradoxides Plate pleuræ pleural portion posterior margin Potsdam Ptychoparia pygidium pyroxene Radoboj referred ridge rocks Rott sandstone scapular Scenella Scudd segments septa shales shell side Silurian spines strata striæ surface Taconic Tertiary Thompsoni thorax transverse Troy U. S. National Museum Upper Cambrian vein ventral valve Vermont Walcott width wing