ERRATA. 



Page 29. line 4. for " Dorsaliados, " read " Dorsalidce." 

 31. line 1, for " Maldaniadce " read " MaldanidcB." 

 36. line 1. of note, for " Magillus " read " Magilus." 

 49. line 10. for " Cumming " read " Cuming." 

 173. line 8. for " Clausilea" read " Clausilia." 



line 15. for e< Clausilece" read " Clausilics." 

 188. under first wood-cut add " c, young state of 

 Valvata ; a, 6, more advanced. " 



