VOL. I. PLATE III. 



FIG. 13. _. The tetrahedron. 



2 



o 



FIG. 14. _. The same, in inverse position. 



* 



o' 

 FIG. 15. _i A trigonal-dodecahedron. 



/w 



c 



f~\ 



FIG. 16. -<&- The same, in inverse position. 



m 



T> 



FIG. 17. ~. A digrammic tetragonal-dode- 



, cahedron. 



T> 



FIG. 18. The same, in inverse position. 



