The collection of Fossil Vertebrata in the National Museum at Washington is at present insignificant; and the only type-specimens observed by the writer are the fish-remains described by Prof. Leidy under the names of Clupea humilis, Cladocyclus occidentalis, Phareodus acutus, and Lepidosteus simplex, besides some fragmentary specimens from the Hamilton Group made known by Prof. J. M. Clarke in the Bull. U. S. Geol. Survey, No. 16 (1885). The palæontologist interested in the lower vertebrates, however, finds much to occupy him in the collection of recent fish skeletons made by Prof. Theodore Gill, who has contributed perhaps more than any other ichthyologist to our knowledge of those parts with which the palæontologist is alone able to deal. At the time of the writer's visit, Prof. Gill was occupied with an investigation of the skeletal anatomy of the eels; and a large number of beautiful drawings of the cranial osteology of various great groups of bony fishes, as yet in the Professor's portfolio, are intended for the basis of a forthcoming general work, to which all who are interested in palajichthyology will anxiously look forward.