III.—A Revision of the Group of span class="italic"Nautilus elegans/span, J. Sowerby

Owing to the defective character of Sowerby's description and figure of Nautilus elegans, the latter has been variously interpreted, specimens belonging to other species having been frequently referred to it. In the present paper we shall show what is the true N. elegans, tracing the history of the type-specimen, which we have been fortunate enough to identify in the collection of the British Museum. This done, we shall proceed to describe three other species, viz. N. elegantoides, d'Orbigny, N. Atlas, Whiteaves, and N. pseudoelegans, d'Orbigny, all evidently allied to N. elegans, and forming with it a group of species which may be appropriately called the “Group of Nautilus elegans.”