ERRATA. 
Publication 44, Geological Series, Vol. 1, No. 7. 
Fig. 2 should stand so that the edges ab, ba, etc. are vertical. 
Fig. 6 should stand at right angles to the position given. 
p. 236, line 7. For 4135 read 3415. 
line 8. For 5143 read 4135. 
p.241. The symbols -- 2 Rg2and -j- +R 3 should stand opposite 
the letters w and ¢ respectively. 

