Illustrations have been moved next to the text which they illustrate, and may no longer match the locations given in the List of Illustrations.

Page headers have been converted to sidenotes.

The following apparent errors have been corrected:

• p. 21 "tranverse" changed to "transverse"
• p. 50 "‘the" changed to "“the"
• p. 51 "point," changed to "point."
• p. 51 "foot." changed to "foot,"
• p. 61 "Inprovements" changed to "Improvements"
• p. 67 (note) "right hand" changed to "left hand"
• p. 74 "equaminity" changed to "equanimity"
• p. 92 "countremen" changed to "countrymen"
• (plate) "Plate 12" changed to "Plate 12."
• (plate) "LESSER WEEVER" changed to "LESSER WEEVER."
• p. 138 "assailent" changed to "assailant"
• p. 145 (note) "Introd. to Conchology" changed to "Introd. to Conchology"
• (plate) "ANGLED-CRAB" changed to "ANGLED-CRAB."
• p. 230 "Plymouth" changed to "Plymouth."
• (plate) "PURPLE-HERMIT CRAB." changed to "PURPLE HERMIT-CRAB."
• p. 300 (note) "right hand" changed to "left hand"
• p. 300 (note) "XXXIV" changed to "XXXIV."
• p. 310 (note) "XXXV" changed to "XXXV."

The following are used inconsistently in the text:

• BeroË, BerÖe and Beroe
• Brittlestar and Brittle-star
• Corkwing and Cork-wing
• dÉbris and debris
• footstalk and foot-stalk
• honeycombed and honey-combed
• Keyhole and Key-hole
• Longworm and Long-worm
• zigzag and zig-zag