A REVISION OF THE SUBSPECIES OF PASSERCULUS 



ROSTRATUS (CASSIN). 



Harry C. Oberholser. 



Three forms of the large-billed sparrow are at present 

 recognized. These are Passerculus rostratiis rostratus (Cassin), 

 from southern CaHfornia and Lower California; Passerculus 

 rostratus guttatus Lawrence, from Lower California; and Passer- 

 culus rostratus sanctonim Ridgway, also from Lower California. 



These birds have been of much interest to ornithologists, 

 partly by reason of the illusiveness of the breeding grounds of 

 two of the forms. Moreover, they have always presented a 

 difficult problem for the systematist, and scarcely any two 

 authors have agreed concerning them, as the different arrange- 

 ments of the forms bear witness. The present writer has for 

 a number of years paid particular attention to these sparrows, 

 and now the identification of a series of specimens of this species 

 from southern California, collected by Mr. E. J. Brown for the 

 L^nited States National Museum, and of another small lot 

 from Lower California, obtained by Mr. Luther J. Goldman for 

 the Biological Survey, has made necessary a further examination 

 of all the other material in the collection of the United States 

 National Museum, including that of the Biological Survey. The 

 types of all the described forms have been available, including 

 the type of Passerculus rostratus rostratus, in the Academy of 

 Natural Sciences of Philadelphia, and that of Passerculus 

 rostratus halophilus, together with the type series of the latter, 

 now in the collection of Dr. Jonathan Dwight, of New York. 

 In addition to the birds in the above-mentioned collections, 

 we have examined also all the sparrows of this species in the 

 Museum of Comparative Zoology, at Cambridge, Massachusetts, 

 the American Museum of Natural History, and the private 

 collections of Mr. William Brewster, Mr. A. C. Bent, Dr. Louis 

 B. Bishop, and Dr. L. C. Sanford. Thus we have worked over 

 altogether 443 specimens, a series apparently adequate to 

 settle most of the perplexing questions that have arisen 

 regarding this group. The study of this extensive material 



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