ERRATA. 



Page i8, line 6: for Plumaria phcmulina read Plumulina pluma- 

 ria. 



do do 



for sondstone read sandstone. ?^ j 



for 6". mesrstrialis read S. mesastrialis. 

 for Devo- read Devonian. 

 14: for py. read pp. 



We regret to say that Part III does not contain a discussion 

 of all the species mentioned by the writer in Part II. Lunuli- 

 cardium fragile is perhaps the most serious omiSvSion. — Ed. 



