74 



VARIATION IN LEPTINOTARSA. 



above that of undecimlineata, and multitczniata shows two modes, the high 

 mode being the same as that of signaticollis and the low one the same as 

 that of oblongata. 



The percentage of individuals found in the modal classes is shown in the 

 following table : 



Table 19. Comparison of the per cent of individuals in the modal classes of the dif- 

 ferent species of the lineata group. 



In this table it is apparent that where the percentage of individuals in 

 any modal class is high when the pronotum is taken as the standard, the 

 per cent of individuals in the corresponding class of the epicranium is also 

 high and in most of the species higher than in the pronotum. In only a 

 few cases does the percentage of individuals in the modal class of the epicra- 

 nium fall below that of the corresponding class of the pronotum, and even 

 in these cases the differences are slight, being only 4 per cent in L. signati- 

 collis and L. diversa. 



The range of variation in the color values in these two parts of the body 

 is also of interest. It is shown briefly in the following table : 



Table 20. Comparison of the range of variation of color proportion in the pronotum 

 and epicranium of the species of the lineata group. 



