54 



Trans, Acad. Sci. of St. Louis. 



can be arranged in the form of regular polygons of 

 3^ 4, 5, ... . sides for the respective cases, thus : 



1 3 



A 



O 



5 



6 



A 



12 



10 



16 



♦ <$> 



22 



^ ^ 



15 



A A 



25 



35 



6 



o 



1 8 



o 



15 



o 



28 



21 



1 7 18 34 



40 



