ADDITIONAL ERRATA 
Page 19, 18th line from bottom, after Grypbaea Pitcheri insert var. navia. 
G2, 12tli “ “ for P. pustulosus read P. rogersi. 
for T. roissyi read Spirifer lineatus. 
lltli “ “ for Millipunctata read Millepunctata. 
for Spirifer musebachanus read Spirifer cameratus. 
for S. pilosus read S. Kentuckensis. 
G3, 2d “ top, for Spirifer Pilosus read Spirifer Kentuckensis. 
for Millipunctata read Millepunctata. 
“ 9tli “ “ for Terebratula roissyi read Spirifer lineatus. 
101, 13th “ “ after Terebratula, for Shwyd road Lhwyd. 
119, No. 114, for Productus pustulosus read Productus Eogersi. 
“ “ 117, for Terebratula roissyi read Spirifer lineatus. 
“ “ 118, for Millipunctata read Millepunctata. 
“ “ 119, for Spirifer musebachanus read Spirifer cameratus. 
“ “ 119-f, for Spirifer pilosus read Spirifer Kentuckensis. 
Note. —The necessity of the changes of nomenclature in the references to the fossils here noticed are explained in one 
case by the note on page 102, and the synonymy under Spirifer cameratus, same page, will explain the reason of the change 
in that instance. The fossil referred to Productus pustulosus proves, on comparison, to be a distinct species ; and the speci¬ 
mens referred to Terebratula roissti prove to be Spirifer lineatus —these species resembling each other in form. Mr. 
Conrad has very recently proposed for the narrow and much incurved variety of Gryphiea Pitciieri, (if it be indeed that 
species,) the name of Navia. 
