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 : 



3 



A 



4 



O 



O 



A 



12 



^ 



21 



10 



16 



22 



1 6 15 28 



17 18 



■ o 



65 



