EREATA. 



Owing to the haste with which the proofs were revised by 

 authors, the toUowing corrections and emendations by authors 

 still require to be made. [Ed ] 



On plates 4 and ?, read " Vol. I," for Vol. II." 



Page 147, line 13 from bottom. For 461, 22," read "vol. 161, p. 511." 



148, ... 6 from bottom. For " have," read " has." 



170, ... 5. For '^ SjJiriferim," read '^ Sptriferina." 



170, ... 6. For " (?y," read " 6^/-y." 



171, ... 7 from bottom. For "position," read "condition." 



172, .. 18. For ^^variablis,'' read ^^ variabilis.'^ 



172, ... 10 from bottom. For " clayshell," read " clay-shale." 



178, .. 12 from bottom. For '^ Fieuratomaria,^' read ^^ Fleu- 



rotoynaria^ 



182, ... 6 from bottom. For " 5" 6'"' "read 5' 6"" 



184, ... 7 from bottom. For " remaked," read "remarked." 



.. .. 187, ... 13. For "phosphatical," read " phosphatised " 



194, ... 16. For '■'• vca IcnooplKxa,'' read " var leucophcea." 



199, ... 2. For " Tissidens," read " Fissidens," 



206, ... 21. For "problems," read "problem." 



210, ... 32. Cancel the whole of the line. 



210, ... 33. For "the," read "The." 



211, ... o. For " lineal, read " linear, 



211, ... 12. Ditto ditto 



211, ... 6. For "sum," "sum," read "product," " sine." 



213, ... 1 For sentence beginning "on the other hand," 



read "on the one hand, there mubt betaken 

 into account the changing and constantly 

 lessening divergence of pencils of large aper- 

 tures after entering the objective : on the 

 other hand, the opposite condition, «kc." 



216, ... 17. For " in," read " on." 



217, ... 4. For "two first, read "first two." 



217, ... 21. For every improvement," read "every later 



improvement," and cancel "since." 



218, ... 7. For " affected," read " effected." 



219, ... 27. For "as," read " and." 



221, ... 16. For "In the," read "IX. In the." 



222, ... In note, two lines from bottom, for "Roberts' " 



read "Nobert's." 



228, ... 9. For refracted," read " refrangible." 



229, ... 28. For "thing," read "things." 



23U, ... 12. For " 8o long as tlie angle, &c. " read " As Ions: 



as the size of aperture remains so large that, 

 &c." 



230, ... 29. For " definite kind," read " prescribed form.'" 



231, ... 8. For " illuminations," read " illumination." 



234, ... 19. • For " sm-f ace," read " surf aces. " 



240, ... 11. For "alteration," read " alternation.'' 



