ERRATA. 



Pa^ 12, line 18, for Ulbich read NicHOLSoif. 



Pag:e 16, line 11, for N. s. o., read Hail. 1886. 



Pag'e 40, lines 6 and 7 from bottom, for Rhinodictya read Rhikidictta. 



Pag-e 41, line 15, for Rhinodictta read Rhinidictya. 



Page 74, lines 2 and 3, for 5, 6, read 6, 7. 



Page 83, line 15, for figs. 30-32, read figs. 30-33. 



Page 84, line 9 from bottom, for 26 read 27. 



Page 96, lines 7 and 9, foi- 37, 38, read 36, 37. 



Page 103, line 21, fer 7, 8, read 7-10. 



Page 106, the name Fknestblla pbrtkndis was given to a Niagara species in 1879, and the present species 

 is named FBjrE.STKLLA Prodtana by S. A. Miller, and the name should have been adopted in this volume. 



Page 110, line 4 from bottom, for 22, 24, read 22-24. 



Page 120, line 4 from bottom, Fbnkstella (Rbtbpobina) coalbscbns is a new species. 



Page I.IH, line 2, insert plate xliii, fig. 1. 



Page 178, line 7 from bottom, for fig. 6, read fig. 2 



Page 179, line 2, for fig. 8, rea<i fig. 9. 



Page 182, line 18, for Erie county, read Genesee county. 



Page 189, line 1 from bottom, for Erie county, read Genesee county. 



Page 193, line 3, Nkmataxis simplex is a new species. 



Page 193, line 9 from bottom, for Erie county, read Genesee county. 



Page 194, line 14, foi' Erie county, read Genesee county. 



Page 215, line 5 from bottom, for 22, read 20. 



Page 239, line 9, Coscikblla blboantdla is a new species. 



Page 243, line 16, for Erie county, read Genesee county. 



Page 245, line 1, Stictopoba bbctalinea is a new sjiecies. 



Page 246, line 1, Stictopora tumulosa is a new species. 



Page 249, line 9 from bottom, for .15 to .25 mm., read 15 to 25 mm. 



Page 266, line 8, Pbismopora lata is a new species. 



Page 28;^, line 17, for 1849, read 1844. 



Kxplatiation of plate xxiv under Rbckptacclitbs ikfuhdibulifobmis for page 289, read page 290 ; under 

 Ih<;h ADITK8 8<ju AM IKBB, for page 290, read page 291 ; under IscH aditbs bdbsifobmis, for page 290, read page 291 . 



