6 
this end in view, changes have been made freely, and the portions re. 
lating to the geographical distribution of the various species and sub- 
species have been largely rewritten. In this task the editor has received 
invaluable assistance from Mr. Robert Ridgway, Curator of Birds in 
the U. S. National Museum. 
The nomenclature adopted is that of the new Check List of the 
American Ornithologists’ Union, with the additions and corrections 
contained in Ridgway’s Manual of North American Birds, which, for- 
tunately, became available just as this report was going to press. The 
number in brackets following each name is that which the species bears 
in Ridgway’s Nomenclature of North American Birds, as published in 
Bulletin 21 of the U. 8S. National Museum, 1881. 
The admirable map which accompanies this report has been prepared 
under the supervision of Mr. Henry Gannett, chief geographer of the 
TJ. 8. Geological Survey. 
My own connection with the report has consisted in bringing together 
under the head of each species the matter contributed separately for the 
two years; in arranging it in accordance with the nomenclature of the 
American Ornithologists’ Union; in revising* the systematic portion 
of the report (Part Second); in incorporating the original Appendixt 
into the body of the text, and in the editorial revision of the manu- 
script of the whole report—a labor which, for the past year and a half, 
has consumed all of the time not required in the performance of my 
routine official duties. ‘ 
C. Hart MERRIAM, 
Editor. 
WASHINGTON, D. C., July 20, 1887. 
* This revision has consisted in rewriting the habitats of most of the species and 
subspecies; in casting out some forms which had been included upon erroneous 
identification or insufficient evidence; in correcting statements of fact; in transfer- 
ring (in a few cases) the notes sent under a stated species or subspecies to a nearly re- 
lated species or subspecies known to inhabit the region under consideration to the 
exclusion of the form reported; in the addition of a number of species and subspecies 
now known to inhabit the region; in the insertion of additional matter under species 
already given; in the interpolation of authorities for second-hand statements; and 
in the omission of matter of questionable reliability. In all of these directions the 
editor feels that the report is susceptible of still further improvement, but want of 
time and reluctance to longer delay the publication of an already long-delayed and 
much-clamored-for document must be his excuse for its incompleteness and imper- 
fections. 
+The original appendix consisted ofa very briefly annotated list of about one hundred 
and forty birds supposed to inhabit the District, but concerning which no reports had 
been received from our observers. Some of these have been aliminated, as resting upon 
insufficient evidence ; the remainder, for the convenience of those who use this book, 
have been incorporated in their proper places in the general text, accompanied by a 
statement of their geographical distribution, and such other facts of interest as might 
be added without too greatly increasing tue bulk of the report. 
