(Cnnaftn 
ilcpaitiinMit IHines 
Hon. LOUIS CODERRE, Minister; 
R. G. McCONNELL, Deputy Minister. 
Qfcalngiral S»mj 
Museum Bulletin No. 20 
GEOLOGICAL SERIES, No. 29 OCTOBER 8, 1915 
AN EURYPTERID HORIZON IN THE NIAGARA 
FORMATION OF ONTARIO 
by 
M. Y. Williams 
OTTAWA 
Government Printing Bureau 
1915 
No. 1574 
