VOL. I. PLATE VI. 



FIG. SI. D. The dodecahedron. 

 d 



FIG. 32. An. A hexahedral trigonal-icositetra- 

 a hedron. 



FIG. 33. Bn. An octahedral trigonal-icositetra- 

 b hedron. 



FIG. 34. Cn. A digrammic tetragonal-icositetra- 

 c hedron. 



FIG. 35. Tn. A tetraconta-octahedron. 



t 



FIG. 36. Derivation of the tessular forms from the 

 hexahedron. 



