The scientific publications of the National Museum include two series
known, respectively, as _Proceedings_ and _Bulletin_.
The _Proceedings_ series, begun in 1878, is intended primarily as a
medium for the publication of original papers based on the collections
of the National Museum, that set forth newly acquired facts in biology,
anthropology, and geology, with descriptions of new forms and revisions
of limited groups. Copies of each paper, in pamphlet form, are
distributed as published to libraries and scientific organizations and
to specialists and others interested in the different subjects. The
dates at which these separate papers are published are recorded in the
table of contents of each of the volumes.
The series of _Bulletins_, the first of which was issued in 1875,
contains separate publications comprising monographs of large zoological
groups and other general systematic treatises (occasionally in several
volumes), faunal works, reports of expeditions, catalogs of type
specimens, special collections, and other material of similar nature.
The majority of the volumes are octavo in size, but a quarto size has
been adopted in a few instances. In the _Bulletin_ series appear volumes
under the heading _Contributions from the United States National
Herbarium_, in octavo form, published by the National Museum since 1902,
which contain papers relating to the botanical collections of the
Museum.
The present work forms No. 210 of the _Bulletin_ series.
Remington Kellogg,
_Director_, _United States National Museum_.