ERRATA. 
Page Line 
317 o for ** [117] ” read ** [317] ” at the top of the page, 
375 Running title,ybr prevention” read ** preservation.” 
439 4 for ‘‘ Plate XXVII.” read « Plate XXIX.” 
445 3 from bottom, ybr.** having ” read ** leaving.” 
449 18 for 1092 ” read ** 8092.” 
457 * from bottom, ybr ** there were mixtures” read ** these were mixtures.” 
463 "I In the column of differences, the numbers should be placed to stand 
464 J intermediate between those of the column of parts. Also, dele ** 23.4” 
in line 8 of the former column, and bring up the remaining differences 
each a line higher. 
492 2 for ** place ” read ** plane.” 
