PLATE XIII. 



Figure 1. Leperditia Hisingeri, Schmidt, a, left valve ; b, ventral edge ; c, end 



view. Magn. 3 diam. Long Point, Lake Winnipegosis. 



" 2. var. fahulina, nov. Left valve. Magn. 3 diam. Foot 



of the Grand Rapids. 



" 3. a, right valve ; b, ventral edge ; c, end view. 



Magn. 3 diam. Long Point, Lake Winnipegosis. 

 var. gihbera, nov. Left valve. Magn. 3 diam. Long 



Point, Lake Winnepegosis. 



5. vsLr. fabvlina, nov. Left valve. Magn. 3 diam. Long 



Point, Lake Winnepegosis. 



6. Ventral edge of a left valve. Magn. 3 diam 



Long Point, Lake Winnepegosis. 

 7. Leperditia pJiaseolus (Hisinger). a, right valve ; b, edge view ; c, end 



view. 

 8. Right valve. Magn. 3 diam. Roche Rouge, Saskat- 

 chewan River. 



9. Hisingeri, Schmidt, a, left valve ; Magn- 2 diam. ; b, portion of 



postero-dorsal region. Magn. 25 diam. Long Point. 



10. aZto, Hall. Interior of left valve. Magn. 3 diam. 



IL a, interior of right valve; Magn. 3 diam. ; b, portion 



of inside of hinge-line. Magn. 25 diam. Figs. 10 and 11 

 from Schoharie. 



12. baUhica (Hisinger), var. Gue/phica, nov. a, right valve : b, 



veniral edge. 



13. a, left valve ; b, ventral edge ; c, end 



view. Figs. J 2 and 13. Magn. 3 diam. Durham, Ontario. 

 14. Aparchites Tyrrellii, nov. a, right valve ; b, edge view ; c, end view. 

 Magn. 40 diam. Black Island, Lake Winnipeg. 



