The report results from a contract (Nonr-38700) between the Office of Naval Research and the Museum of Natural History of the University of Kansas. Field headquarters were at the Arctic Research Laboratory at Point Barrow, Alaska. Professor John Fields and Dr. Louis O. Quam of the Office of Naval Research, Professor Ira L. Wiggins, Scientific Director of the Arctic Research Laboratory, and Mr. M. R. Lipman of the University of Kansas Regional Office of the Office of Naval Research are four of the persons to whom I am deeply indebted. J. Knox Jones, Jr., and Edward G. Campbell, students at the University of Kansas, participated in the field work and deserve credit for a large part of the accomplishment registered in the field. The author is greatly indebted to Professor E. Raymond Hall for assistance at many stages in the work. I am grateful to Professor Harrison B. Tordoff for numerous suggestions and for verifying the identifications of the specimens. The skeletons were identified by measurement and comparison of feet, bills, and the dried, flat skins that had been removed and labeled with the field numbers of the corresponding skeletons. Where subspecific identification was difficult because of the fashion in which the material was preserved it should be understood that the subspecific name assigned was based largely or entirely on geographic probability. This is wholly true for sight records. Robert G. Bee read the manuscript in its entirety and offered editorial comments and my wife, Annette, typed the manuscript and made numerous corrections. The names of several other individuals who rendered assistance appear at appropriate places in the following pages. ITINERARY Camps and collecting localities on the Arctic Slope of northern Alaska in 1951 and 1952 (Bee and Jones, July 3-September 6, 1951; Bee, September 6-11, 1951; Bee and Campbell, June 14-August 25, 1952; Bee, Campbell, and Hall, August 26-September 12, 1952) were as shown in Fig. 1. Camps, and localities in the vicinity of each camp, are arranged geographically from north to south. The localities listed below under camps are only those which one or more of us (Bee, Campbell, Jones and Hall) visited. Travel between camps was by airplane; heavy black lines show routes followed. Point Barrow (1951: July 3-5, 10-12, 18-20, 27-29, Aug. 5-7, 28-30, Sept. 4-11. 1952: June 14-24, Aug. 23-27, Aug. 31-Sept. 12). Longitudes and latitudes taken from U. S. Coast and Geodetic Survey map No. 9445, 2nd edition, Point Barrow and vicinity, corrected May 21, 1951. Point Barrow, 156 deg.27'25", 71 deg.23'11", 3 ft. (June 20, 21, Aug. 25, 1952). Point Barrow, 156 deg.30'00", 71 deg.22'10", 0 ft. (Sept. 11, 1952). 4-1/2 mi. SW Point Barrow, 5 ft. (Sept. 7, 8, 1951), but in the second year (June 14, 16, 1952) specimens from this same place were inadvertently labeled at "Birnirk Mounds, 156 deg.36'02", 71 deg.20'40", 8 ft.".