PLATE 19 

 Spirifer arenosus (Conrad) 



Page 83 



i Lame smooth internal cast of a ventral valve 



2, 3 Dorsal and profile views of conjoined valves, the ventral valve being 



preserved as an internal cast 

 4 Internal cast of dorsal valve 



Locality. Cunningham's camp, near Matagamon lake 



Spirifer primaevus Steininger var. atlanticus Clarke 



(See plate 20) 

 Page !j 



5-12 A series illustrating tin- internal (5, 6, 9, 10, n) and external (7, 8, 



12) characters of this shell 



Locality. Tomhegan point. Moosehead lake 



204 



