OX PYROXEXIC COMPXXEXTS IX CERTAIN VOLCANIC ROCKS. 89 



their ends simple spines of Augite (pag. 84). 

 Fio-, 20. — The smaller forms of the Ansnte microliths. 

 Fig. 21. — The 'Rhombic lamelW; the two individuals as a twin of 



the Carlsbad type (pag. 71). The upper individual shows an 



extinction-angles of 40° with the edjre of V : M. 

 Fig. 22. — The same ; with the development of the face y, and the 



pyramidal faces in the zone of M : x. 

 Fig. 23. — The same ; the pyramidal faces being very distinctly seen 



in this crystal. 



