NO. 2179. 



VARIATION IX GARTER SNAKES— THOMPSON. 



357 



the garter snakes assume a role of particular economic interest. They 

 should become a special object of care and protection on the part of 

 florists and gardeners. 



COMPARISON BETWEEN SAN FRANCISCO AND SAUSALITO SERIES. 

 There is presented for comparison in the following parallel columns 

 a summary of the variations in the series from the two localities on 

 either side of the Golden Gate: 



Scale rows: 



21—23—21—19—17 . 



21—19—17 



19—21—19—17 



19_2l_19— 17— 15 . 



19—17 



19—17—15 



19—17—15—13 



17—19—17—15 



17—15 



15—17—15 



Asymmetrical 



Preocular: 



1 normal 



1-2 asymmetrical — 



2 bilateral 



2-3 asymmetrical — 



Postoculars: 



3 normal - 



3-2 asymmetrical — 

 3-4 asymmetrical — 

 2 bilateral 



4 bilateral 



Anterior temporal: 



1 normal 



1-2 asymmetrical — 



2 bilateral 



Posterior temporals: 



2 normal 



2-3 symmetrical 



3 bilateral 



Supralabials: 



8 normal 



8-7 asymmetrical . . . 

 8-9 asymmetrical- . . 



Infralabials: 



10 normal 



10-11 asymmetrical . 

 10-9 asymmetrical. . 

 10-8 asymmetrical. . 



9 bilateral 



9-8 asymmetrical. . . 

 8 bilateral 



Anal: 



Entire normal 



Divided 



Urosteges: 



Paired normal 



1 to 4 entire 



Gastrostegea (plates) . . . . 

 Urosteges (plates) 



San Francisco. 



78 



2 

 4 

 2 



100 



94 



147-166 

 66-85 



66 



10 



72 



28 



145-164 



66-85 



