The Swifts 



Distribution. Abundant in the Great Basin. It occurs 

 as far north as Oregon and is common in the mountains of eastern 

 California, Idaho, Nevada and Utah to an altitude of 8,000 feet; 

 most abundant on the sage-covered plateaus. Southward 

 it extends through the deserts, into northern Mexico. 



* 



Regarding identification. At no part of this chapter has the 

 writer gone into elaborate details concerning the possible 

 necessity of a distinct, varietal name for certain variations, or 

 combating the validity of some species that bear a close resem- 

 blance to others. Before commencing the chapter, he examined 

 a large series of specimens and compared the various species with 

 the technical descriptions in the regular works of scientific nomen- 

 clature. His decisions resulted at the time, in omitting certain 

 alleged species that he did not consider strong and distinct. 

 That part of the work was then looked upon as a closed chapter, 

 and it is not the writer's idea to burden the student with long 

 explanations as to how he arrived upon the list of species as 

 they stand. The point has been to treat a very confusing genus 

 in a manner that will present it to the student from the stand- 

 point of a bird's-eye view. The genus Sceloporus is worthy of 

 an elaborate monograph, but the proper compilation of this 

 would take half a lifetime and study of the combined collections 

 in the museums of the world besides many additional specimens 

 to solve certain problems now standing. 



In comparing specimens of Sceloporus the student should 

 count the scale rows, note the proportionate size of the body 

 scales, study the head plates and compare the colouration of 

 one series with another. The locality is also an important 

 factor and will aid in the case of old specimens of exceedingly 

 brilliant colours, as the dots and splashes of brilliant hues will 

 fit into none of the descriptions. An occasional specimen will 

 exhibit a head scalation that seems to be outside the definitions 

 of all the divisions. In such a case, locality counts and helps 

 in removing the puzzling individual from its indefinite status. 



142 



