ERRATA OBSERVED. 
93 line 3 from bottom, for black read block. 
201 11 from top, for 2, 9, read 29. 
224 4 from bottom, for 24, read 30. 
234 9 from bottom, for variabilis, read reticulatus. 
23T 1 from top, for Bolland, read Grassington. 
— 4 from top, add ‘ slightly pointed.’ 
