168 Bangs What is Icterus Gualanensis Underwood? 



ends with the forehead in /. giraudii) extended hack tn beyond 

 the eye, where it ends in a broken line. In /. rtidanocephalus 

 the whole head down to the upper part of the neck is black. 



The accompanying drawing from a sketch made by Miller 

 shows the distribution of black upon the head in the three species. 



Gualanensis 



/ Giraudi 



.' * 



Melanocephalus 



The measurements of the type are well within the extremes 

 of those of Icterus giraudii, which varies considerably in size' 

 throughout its extensive range. They show the bird to have 

 been larger with a larger bill than the maximum size reached 

 by /. melanocephalus, and altogether larger than Icterus prosthe- 

 melas, the young of which Ridgway suggests (Birds of N. and 

 Mid. Am., Part H, p. 295, footnote, and in synonymy of /. 

 prosthemelas, with a query, p. 271.) /. gualanensis might pos 

 sibly be. 



Therefore, Icterus gualanensis is, so to speak, an example of 

 I. giraudii perfectly typical in every respect except in having 

 the black of head extending somewhat farther back. It conies 

 from a region almost in the middle of the range of I. giraudii, 

 so that it can hardly be a geographical form of that species, and 

 the chances seem strongly in favor of its being a " freak." Un 

 fortunately, however, this can not be considered as proved, and 

 /. gualanensis must take its place among the number of ' ' species ' ' 

 of tropical American birds that rest on the strength of a single 

 peculiar individual. Cases of this sort are not uncommon 

 among the humming birds and Hartert's method of treating 

 them in his Trochilidse * seems to me the best that could be 



* Das Tierreich, Berlin, 1900. 



