92 NORTH AMERICAN BIRDS. 



• 



fifty specimens, including examples from all parts of its range. Upon a 

 close inspection of all the specimens in this extensive series, I was very 

 much STirprised to find so little variation ; indeed, all the specimens are so 

 much alike that a detailed description of the colors of one would answer for 

 almost any individual. The shade of color varies mainly according to the 

 age of the feathers, those newly acquired having a darkness of tint and a 

 softness of texture not seen in those more w^orn (as in midsummer dress), 

 which have a bleached or faded appearance. I fail entirely to detect tlie 

 different styles of plumage wdiich Mr. Cassin has described, and his diagnoses 

 of two supposed species will not at all hold good when ajjplied to speci- 

 mens from either of the two regions which they were considered to char- 

 acterize. 



Examining critically tlie large series at my command, I find that the 

 principal discrepancy among individuals is the amount of feathering on the 

 tarsus ; this extending to the toes was supposed to characterize the A. cuni- 

 cularia of North America the habitat of which was considered as restricted 

 in North America to the west of tlie Eocky Mountains (see Cassin, Birds of 

 North America, as cited above) ; the nearly naked tarsus was believed to be 

 characteristic of the A. hyj)ogcea, as restricted, and the habitat assigned to 

 this was " from the Mississippi Eiver to the Eocky Mountains." Now, 

 dividing the series under examination into two sets, according to this fea- 

 ture, we have, first, cunicnlaria from the following localities : from the Eio 

 Grande, all specimens but one ; Tongue Eiver, Montana ; and Petaluma, 

 Santa Clara, aiul San Francisco, California. Next, hi/jjogcea represents the 

 following localities, besides places within the range ascribed to it : Utah ; 

 Lower California, including Cape St. Lucas, all specimens ; San Diego, Cali- 

 fornia, several specimens ; Santa Barbara, San Francisco, Sacramento, and 

 Fort Tejon, California ; and Tamaulipas, Mexico. 



Though we have but one species or form in North America, the South 

 American bird is different : this is the true cunicularia of Molina, and 

 though not specifically distinct from our bird, is nevertheless an easily 

 recognized geographical race. It is larger, the wing measuring from 7.00 to 

 7.50, instead of 6.40 to 7.00 ; the brown of the plumage is appreciably darker 

 than that of most specimens of hypoga;a, but less extended ; on the outer 

 web of the primaries the white spots are larger, — sometimes confluent along 

 the edge, — and on their inner webs the white largely prevails, the dusky 

 bars appearing only towards the ends ; the outer tail-feather is almost 

 wdiolly white, instead of having brown bars, broader tlian the white ones. 

 Of the var. cunicularia there are eight specimens in the collection (chiefly 

 from Paraguay, Buenos Ayres, and Chile), while numerous others, in various 

 collections, have been examined besides. All the American forms of this 

 subgenus seem clearly referrible to one species, as being at the most but 

 geographical races. 



Habits. The Burrowing Owl of North America inhabits the country 



