6o ALBERT JOHANNSEN 



to anorthoclase rocks without mafic minerals, and would divide the 

 basic plagioclase rocks, now called anorthosites, into labradites and 

 anorthitites, according to the kind of plagioclase present, pre- 

 sumably dividing the bytownite rocks between them. Since most 

 anorthosites are labradorite rocks, the term may well be confined 

 to the labradorite-bytownite rocks of Class i, Order 3, leaving the 

 anorthite rock, anorthitite, in a class-by itself (1415). 



Labradite Turner. 



B3rtownitite. 



Leucobasalt. The extrusive equivalent of anorthosite. 



CLASS I, ORDER 4 



(1414) Leuco-anorthite-monzogabbro. A simpler name should 

 be used here when a rock near the center point is described. 



(141 5) Anorthitite Turner." See note under (13 15). 



[To be continued] 



