1921 .] Recently published Ornithological Works. 559 
Columbia to southern California, and exhibit considerable 
variation, not only in plumage but in so-called structural 
characters, such as size of bill and length of tail. Nearly 
all the western races winter in California, and so great is 
the variation and so many are the intermediate forms that 
great confusion has arisen and collectors have great difficulty 
in identifying individual examples. 
Mr. Swarth has therefore prepared this very elaborate 
and detailed memoir to clear up the many difficulties 
encountered, and has examined about 1800 specimens, 
including the types of fourteen of the sixteen races, in the 
course of his work, which is obviously of a most accurate 
and detailed character. Four of the more distinct races are 
illustrated by a beautiful plate by Major Allan Brooks; the 
other plates are from photographs of the characteristic 
scenery of the haunts of the birds. 
Apart from its usefulness to Californian ornithologists, 
the paper deals with numerous interesting problems of 
variation, distribution, and migration. 
Swarth on the Birds of Arizona. 
[Birds of the Papago Saguaro National Monument and the neigh¬ 
bouring region, Arizona. By H. S. Swarth. Dept. Interior. National 
Park Service, pp. 1-63; 8 pis. Washington (Govt. Printing Office) 
1920. 8vo.] 
The Papago Saguaro National Monument is a tract of 
land a few miles east of Phoenix in Arizona, set aside to 
conserve certain types of desert vegetation in a region Avhere 
increased settlement is rapidly changing the appearance of 
the land. Some eighty miles further east is a large artificial 
storage reservoir for irrigation purposes, known as Roose¬ 
velt Lake, with a bird reservation around it, and the whole 
region is attracting increasing numbers of visitors for its 
unique and romantic scenery. This little pamphlet is a 
guide to the bird-lover who visits this region, and has good 
accounts of the more common birds to be met with and 
a list of all those likely to be seen. The National Monu¬ 
ments in the United States are now 24 in number and are 
