xiv BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



CORRECTIONS AND INSERTIONS 



All contributors to volume 20 have been invited to send corrections and insertions 

 to be made in their papers, and the volume has been scanned with some care by the 

 Editor. The following are such corrections and insertions as are deemed worthy of 

 attention : 



Page 1, line 2 from bottom ; for ' '.glad to have " read glad to leave 

 ' ' 37, line 20 from top ; for ' ' 1822 ' ' read 1882 

 " 60, line 7 from top ; for " Halfield " read Halfeld 

 " 67, line 17 from bottom ; for " XVII " read XVIII 

 " 72, omit second Katzer title on " Phytopaleontologie " 

 " 98, line 26 from bottom ; for " Petro " read Pieto 

 ' ' 130, line 20 from bottom ; for ' ' Belonstomus ' ' read Belonostomus 

 " 130, line 18 from bottom; for " Rhacolepsis Alfersii" read Rhacolepis Olfersi 

 " 130, lines 16-17 from bottom; for " Rhacolepsis" read Rhacolepis 

 11 130, line 15 from bottom, for " Cladacylus ' ' read Cladocyclus 

 " 160, line 20 from bottom, for " cimpilation " read compilation 

 " 196, insert footnote : A further note on the geometry of faults will appear in 

 volume 21 



Page 350, line 7 from bottom ; for "plate 21, figure 2, and plate 22, figure 1," 

 read plate 21, figure 1, and plate 22, figure 2 

 Page 350, last line ; for "plate 22, figure 2," read plate 22, figure 3 

 " 372, invert figure 4 



" 375, line 11 from top; for "axis " read axes 



" 380, insert footnote : * The absence of planes of symmetry (vertical as usually 

 held) in the simple pyramids of the axial classes is not always apparent to the stu- 

 dent. It is recommended to use drawings and models showing combinations of 

 pyramids of several orders, when the absence of such planes of symmetry becomes 

 at once apparent and the distinction between the symmetry of the axial and hedral 

 classes is clearly seen. 

 Page 380, line 11 from top; for "plates I and II " read plates 31 and 32 

 " 381, line 10 from bottom, for "rotation. In the" read rotation, in the 

 " 381, line 5 from bottom ; for "axis — producing" read axis, producing 

 " 385, line 20 from top ; for " It is elementary " read It is simple 

 11 388, line 2 from top ; for " un- " read uni- 

 " 422, line 21 from top; for " indicate" read indicated 



