PLATE XXXVII. 



*Plectoceras C?) undatum (page 305). 



Side view of a cast of the interior of the septate portion of a large shell that 

 is probably referable to this species, from the Black River limestone at 

 Kingston, Ont. This specimen was acquired for the Museum of the 

 Survey in 1902, in exchange, from the authorities of Queen's University. 



