Natural history of Trinidad and Tobago in the section above on the reptilian fauna of Trinidad and Tobago, a number of species of marine turtles including the leatherback turtle, hawksbill turtle, loggerhead turtle, olive ridley turtle and green sea turtle frequent the waters around and/or nest on some of the beaches of both islands. Whales and dolphins were far more common to Trinidad and Tobago's waters in earlier times, but the very rigorous whaling industry of the 19th century decimated the population of whales in the Gulf of Paria (called 'Golfo de Balena' or Gulf of Whales by Christopher Columbus). Today, dolphins may still be regularly
History of manifolds and varieties spaces with a differentiable or topological structure, while "variety" refers to spaces with an algebraic structure, as in algebraic varieties. In Romance languages, manifold is translated as "variety" – such spaces with a differentiable structure are literally translated as "analytic varieties", while spaces with an algebraic structure are called "algebraic varieties". Thus for example, the french word "" means topological manifold. In the same vein, the Japanese word "" (tayōtai) also encompasses both manifold and variety. ("" (tayō) means various.) Ancestral to the modern concept of a manifold were several important results of 18th and 19th century mathematics. The oldest