This collection contains correspondence on natural history, expecially mollusks, fishes, and birds, and on medicine and social affairs, with references to the British Museum of Natural History. Also included are a paper by Owen on dinosaurs and a synopsis of a course of lectures, 1857.

A miscellaneous collection of letters written by naturalist Louis Jean Rodolph Agassiz concerning a wide range of topics: natural history and naturalists, geology, mineralogy, fossils, publications, expeditions, and the Museum of Comparative Zoology at Harvard, which he founded.