51343 ADVERTISEMENT. The extension of the scope of the National Museum during the past few years, and the activity of the collectors employed in its interest, have caused a great increase in the amount of material in its possession. Many of the objects gathered are of a novel and important character, and serve to throw a new light upon the study of nature and of man. The importance to science of prompt publication of descriptions of this material led to the establishment, in 1878, of the present series of publications, entitled "Proceedings of the United States National Museum," the distinguishing peculiarity of which is that the articles are published in pamphlet form as fast as completed and in advance of the bound volume. The present volume constitutes the fourteenth of the series. The articles in this series consist: First, of papers prepared by the scientific corps of the National Museum; secondly, of papers by others, founded upon the collections in the National Museum; and, finally, of facts and memoranda from the correspondence of the Smithsonian Institution. The Bulletin of the National Museum, the publication of which was commenced in 1875, consists of elaborate papers based upon the collec tions of the Museum, reports of expeditions, etc., while the Proceedings facilitate the prompt publication of freshly-acquired facts relating to biology, anthropology and geology, descriptions of restricted groups of animals and plants, the discussion of particular questions relative to the synonymy of species; and the diaries of minor expeditions. Other papers, of more general popular interest, are printed in the Appendix to the Annual Report. Papers intended for publication in the Proceedings and Bulletin of the National Museum are referred to the Advisory Committee on Publications, composed as follows: T. H. Bean (chairman), A. Howard Clark, R. E. Earll, Otis T. Mason, Leonhard Stejneger, Frederick W. True, and Lester F. Ward. S. P. LANGLEY, Secretary of the Smithsonian Institution. II TABLE OF CONTENTS. Oryzomys talamancæ, Hesperomys (Vesperimus) affinis, new species. Andrews, E. A. Report upon the Annelida Polychata of Beaufort, North Carolina (Plates Harmothöe aculeata, Eunice ornata, Diopatra magna, Ophelina agilis, Polydora commen- salis, Axiothea mucosa, Petaloproctus socialis, Ammochares ædificator, Loimia turgida, Page Bean, Barton A. Fishes collected by William P. Seal, in Chesapeake Bay, at Cape 83-94 355-385 Panopeus areolatus, Panopeus dissimilis, Panopeus ovatus, Panopeus angustifrons, Pano- Description of new genera, species, and subspecies of birds from Costa Rica Deconychura, Premnoplex, new genera. Lophotriccus zeledoni, Pachyrhamphus ornatus, Deconychura typica, Vireo superciliaris, A critical review of the characters and variations of the snakes of North America..... 589–694 Dall, William H. (Scientific results of explorations by the U. S. Fish Commission steamer Albatross). No. XX. On some new or interesting west American shells obtained from the dredgings of the U. S. Fish Commission steamer Albatross, in 1888, and from other sources, Calyptogena, new genus. Trophon cerrosensis, Cancellaria Crawfordiana, Buccinum strigillatum, Buccinum taphrium, Mohnia Frielei, Strombella Middendorfii, Strombella fragilis, Strombella melonis, Chrysodomus ithius, Chrysodomus periscelidus, Chryso- domus phoeniceus, Chrysodomus eucosmius, Chrysodomus (Sipho) hypolispus, Chryso- domus (Sipho) acosmius, Crysodomus (Sipho) halibrectus, Trophon (Boreotrophon) scitulus, Trophon (Boreotorphon) desparilis, Solemya Johnsoni, Calyptogena pacifica, Limopsis vaginatus, new species. Terebratella occidentalis obsoleta, new subspecies. Eigenmann, Carl H., and Rosa S. A catalogue of the fresh-water fishes of South 121-165 Evermann, Barton W., and Jenkins, Oliver P. Report upon a collection of fishes, Chlopsis equatorialis, Xenomystax atrarius, Ophisoma prorigerum, Ophisoma macrurum, (Scientific results of explorations by steamer Albatross.) No. XXII.-Descriptions of thirty-four new species of fishes collected in 1888 and 1889, principally among the Santa |