ITS MODIFICATIONS. 185 



Class d. Acute solid angles replaced by two 

 planes. 



Class e. Lateral solid angles replaced by single 

 planes. 



This class would produce a series of octahedrons 

 analogous to those resulting from modification c of 

 the right rhombic prism, but whose bases instead of 

 being rectangles, would be oblique-angled parallelo- 

 grams. 



Class/. Obtuse terminal edges replaced by single 

 planes. 



2 A 



