°i8q7 1 Nelson, Nezv Birds from Mexico and Guatemala. A'l 



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 oaxacae, new species. Oaxaca Woodgrouse. 



Type, No. 155565, U. S. Nat. Miisevun, Dept. Agric. coll., cJ,Totontepec, 

 Oaxaca, Mexico, Julj 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. 



