PLATE LII. 
Wigs.s eto) (3 (OAMEBOCERASSHENNEPINT, ispe NOVay-easnes se eeeee eee te see ee EEE EEE 
1 and 2 Two views in outline of a very large fragment. 
3 The form of the’terminal septum, showing the size of the sipho. 
From the Galena limestone, near Spring Valley, Minn. 
