This book presents a detailed account of an extensive scientific expedition conducted in 1867 across the equatorial Andes and the Amazon. Led by Professor James Orton of Vassar College, the expedition aimed to explore the natural history and geography of the region. The route traversed challenging terrain, from the coastal city of Guayaquil to the highlands of Quito, through dense rainforests to the Napo River, and eventually to Pebas on the Maranon River. Along the way, the explorers collected numerous specimens of plants, animals, and rocks, compiling a comprehensive record of the region's biodiversity. In addition to their scientific endeavors, the expedition also engaged with local indigenous communities, documenting their languages and customs. The resulting work provides valuable insights into the natural and cultural landscapes of equatorial South America in the 19th century.