ABSTRACT
Ossian Sars' zoological interests gradually shifted from birds to whales, and then, in the middle to late 1850's, he started to study microscopic organisms. During the summer of 1863, Ossian Sars again went collecting, and he studied freshwater and marine crustaceans, this time in the lowlands and mountains of south and southeastern Norway including Christianiafjord (now Oslofjord). Sars gives a description of this asteroid genus completely in accordance with Darwinian principles. After Sars had finished his big mollusc book in 1878, he gave more and more of his attention to crustaceans. Sars also got the opportunity to examine crustacean material from freshwater basins on a completely different continent. A good deal of the material described by G. O. Sars is deposited in the collections of the Zoological Museum, University of Oslo. There are, however, problems associated with the material Sars was not a museum zoologist; he did not seem to have been interested in the technical side of museum collections.
