^"Ig^^^l i?c<:<'«^ Literature. 403 



roosting and feeding places of the Little Blue Heron and American 

 Egret, etc.— J. A. A. 



Nelson on New Birds from Mexico. — Ten of the thirteen species and 

 subspecies here described ^ were obtained by Mr. Nelson and his assistant 

 Mr. Goldman during their expedition to southwestern Mexico in the 

 winter of 1902-03, mostl}' in the States of Guerrero and Michoacan. In 

 most cases the new forms are based on good series of specimens, and 

 several of them seem quite strongly differentiated from their nearest 

 known allies. — J. A. A. 



Nelson's ' Revision of the North American Mainland Species of 

 Myiarchus.'- — The present paper covers the species of the genus 

 Myiarchiis occurring north of the Isthmus of Panama, including those 

 of Cozumel Island and the Tres Marias Islands. Nine species are recog- 

 nized, with ten additional subspecies, of which three of the latter, belong- 

 ing to the laivrencei group, are described as new. In his introductory 

 remarks Mr. Nelson calls attention to the evanescent character of the 

 brighter or more intense colors of the freshly acquired plumage. "This 

 extreme intensity of coloration [of the fresh plumage] quickly passes into 

 a duller condition which continues with but little change through the 

 winter months. In spring the colors gradually fade or become bleached 

 by the sun until in the breeding season the original shades of greenish, 

 olive and gray of the back and the yellow of the under parts are almost 

 lost in the dingy browns and yellows of the frayed plumage." He also 

 calls attention to the wide range of variation in the extent of the dusky 

 pattern of the tail feathers, the non-recognition of which has led to the 

 recording of M. tiuitingi as a bird of southern Arizona, the supposed 

 Arizona specimens of nuttingi proving to be merely females of M. 

 cinerascens. Mr. Nelson, however, adds to the United States list Myiar- 

 chiis crinitus residuus Howe, based on Florida specimens, on the ground 

 of a slight average difference in the length of the bill. This separation 

 had previously been made, on exactly the same basis, by Mr. Bangs and 

 rejected by the A. O. U. Committee as too imimportant for recognition 

 in nomenclature. 



Mr. Nelson discusses at some length the old case of Tyratinula mexi- 

 cana Kaup vs. Myiarchua cooper i Baird, without reaching a positive con- 

 clusion, but gives his reasons for believing that Tyranttula mexicana =z 

 Tyra7i7iitla cinerascens Lawrence, and that the present Myiarckus mexi- 



1 Descriptions of New Birds from Southern Mexico. By E. W. Nelson. 

 Proc. Biol. Soc. Washington, Vol. XVI, pp. 1 51-160, Nov. 30, 1903. 



^ Revision of the North American Mainland Species of Myiarchiis. By E. 

 W. Nelson. Proc. Biol. Soc. Washington, Vol. XVII, pp. 21-30, March 10, 

 1904. 



