ERRATA. 



Pa^e I, top line, tor diatomes read diatoms. 



Page V iSth line from top and page 41. ytli line from bottom, 

 for Blytii read Blyttii. 



Page 40. 22n(l line from top, for Clorospcrmeac read Chloros- 

 perm cat'. 



Page 49, 5th line from bottom, for Berk, read Berkeley. 



Page 87. after R. verritcosa Arescb. insert Plate 5^ J^S- 5- 



Page 118. 20tb line from top. for undulaa read uudulata. 



Page 140. I St line. {(^\ genus read suborder. 



Page i>i3. 2otb line from top. for Daby read Duby, 



