NO. 2051. VARIATIONS OF THAMN0PIII8 ORDINOIDES— THOMPSON. 357 



shields (16 per cent), or the normal eighth and ninth shields (50 

 per cent) being fused. Where the count has been still further 

 reduced to 8, it has been due to the normal third and fourth shields 

 and the normal eighth and ninth shields being fused. 



Per cent. 



10 normal 74 



10-11 asymmetrical 6 



10-9 asymmetrical 12 



10-8 asymmetrical 2 



9 bilateral 4 



9-8 asymmetrical 2 



VARIATION IN ANAL. 



Per cent. 



Entire 90 



Divided 10 



VARIATION IN UROSTEGES. 



The normal condition is for the urosteges to be paired tlu'oughout. 

 Many occur m which there are from one to four entire shields; an- 

 other peculiarity is that these are confined to the first half dozen at 

 the base of the tail. 



Per cent. 



Paired 72 



1 to 4 entire 28 



Extracting from these data shows that the following may be assumed 

 to be the normal conditions: 



Per cent. 



Scale rows 19-21-19-17 66 



Preocular 1 86 



Postoculars 3 80 



Anterior temporals 1 94 



Posterior temporals 2 82 



Supralabials 8 94 



Infralabials 10 74 



Anal entire 90 



Urosteges paired 72 



The following table shows the percentage of normal individuals 

 and the percentage of those that are abnormal in one or more charac- 

 ters: 



Per cent. 



Normal in all characters 14 



Abnormal in one character 44 



Abnormal in two characters 20 



Abnormal in three characters 14 



Abnormal in four characters 6 



Abnormal in five characters 2 



An inspection of the above tables does not evidence any grouping 

 of the variations. There is apparently no tendency for a variation 

 from the normal in one character to be associated with a variation 

 in another character. 



