Vol. XIV 
1897 | Netson, New Birds from Mexico and Guatemala. 43 
Mexico covers a wide range of topographic and climatic condi- 
tions, from tropical coasts to snowy summits of gigantic volcanoes. 
The coast lowlands are humid in some parts and very arid in 
others. Above these rise mountain slopes that are bathed in rain 
and mist during much of the year; and still beyond are the arid 
desert table-lands of the interior. As might be supposed, these 
differences in climate and other physical features result in various 
well defined life zones and give great variety to the animal and 
vegetable life. My knowledge of these climatic and topographic 
features has been of the greatest service in enabling me to define 
with some accuracy the geographical races herein described. In 
no instance is a bird described as new unless the differences from 
its nearest relative are associated with definite changes in the phy- 
sical surroundings. A detailed study of the country with modern 
methods will define the life areas of this region, and the corre- 
sponding variation of many species into geographical races will 
be more definitely known. 
The present descriptions are merely preliminary to a fuller 
account that will be given in a future publication. 
I have to express my obligation to Dr. C. Hart Merriam, Chief 
of the Biological Survey, under whose direction the field work 
was done, for the opportunity to report upon the material obtained. 
During the preparation of this paper I have had the most cordial 
assistance from Mr. Robert Ridgway, Curator of the Department 
of Birds in the National Museum, whose thorough knowledge of 
North American birds was placed freely at my service, enabling 
me to do the work in a fraction of the time that otherwise would 
have been necessary. I am indebted also to Mr. Charles W. 
Richmond, Assistant Curator of Birds in the National Museum, 
for assistance in a number of ways. 
Throughout this paper the measurements given are in milli- 
meters. 
Dendrortyx oaxacze, new species. OAxACA WOODGROUSE. 
Type, No. 155565, U. S. Nat. Museum, Dept. Agric. coll., @, Totontepec, 
Oaxaca, Mexico, July 24, 1894. Collected by E. W. Nelson and E. A. 
Goldman (Orig. No. 2227). 
Distribution.— Mountains of eastern Oaxaca from the Cerro San Felipe, 
near Oaxaca City, to Mount Zempoaltepec, Oaxaca. 
