PLATE XXVIII. 



Pteeinea occidentalis (page 287). 



Figure 1. Side view of a oast of the interior of a left valve of a specimen of this 



species, from the Silurian limestone at Ami Island, near the north-east 



shore of Lake Winnipegosis. 

 Figure 2. Similar view of a cast of the interior of a left valve of a specimen of this 



species, from the Grand Rapids of the Saskatchewan. 

 Figure 3. Side view of the testiferous left valve from Swan Lake, at the head of 



Shoal River, Manitoba, referred to on pages 287 and 288. 



Ambontchia undulata (page 254). 



Figure 4. Side view of a cast of the interior of a right valve of a specimen of this 

 species, from the Ekwan river limestone. 



Ambonychia septentrionalis (page 255). 



Figure 5. Side view of the left valve of a cast of the interior of both valves of a shell 

 of this species, from the Ekwan River limestone. 



Ilionia (?) PARVULA (page 288). 



Side view of the left valve of a shell of this species, from the rocks ex- 

 posed at Ami Island. 



Side view of a right valve of a shell of this species, from the Silurian 

 rocks at Long Point, Lake Winnipegosis. 



Side view of another right valve of a shell of this species, from Long Point. 



Megalomphala robusta (page 257). 



Side view of a large specimen of this species, from the Ekwan River lime- 

 stone. 

 Peripheral view of the same. 



Salpingostoma boreale (page 258). 



Peripheral view of the largest specimen collected, from the Ekwan River 



limestone. 

 Side view of a smaller specimen, also from the Ekwan River. 



