100 



BULLETIN 17 5, UNITED STATES NATIONAL MUSEUM 



in each case more marked to the west than to the east. This indicates 

 a dwarfing in both length and diameter toward the north, away from 



35-37-27 

 32-35-25 

 32-35-24 

 31-35-25 

 31-35-23 

 30-35-25 

 29-35-25 

 29-35-24 

 31-33-25 

 31-33-24 

 31-33-23 

 31-33-21 

 29-33-25 

 29-33-24 

 29-33-23 

 27-33-23 

 29-32-25 

 31-31-23 

 30-31-23 

 29-31-25 

 29-31-24 

 29-31-23 

 28-31-23 

 28-31-22 

 27-31-25 

 27-31-23 

 27-31-22 

 27-31-21 

 29-29-23 

 27-29-24 

 27-29-23 

 27-29-22 

 27-29-21 

 25-29-21 

 27-28-23 



Region No. 12 3 4 5 6 



Figure 51.— Qeographie variation in number of scale rows in PituopMs sayi sayi. 



the probable center of distribution. The greater dwarfing in the north- 

 western part of the range than in the northeastern seems to be in cor- 

 relation with the more severe climate of the former region. Although 



