PLATE IV. 



Pteria (PsEUDorTEUA^) i.'iBR<if;A. Y;ir., (page o2). 



Fiiiuie 1. Lateral view of a specimen IVom the Bow Eiver. shewing the 

 riglit \'alve- 



Geryillia recta, \iiv. BoREALis (page o5). 



Figure l'. Side view of a left valve froni tlie Belly Kiver. 



2((. Cast of the interior of the closed valves, from the South Saskat- 

 chewan, shewing the imiu'essions made by the muscular 

 scars of the right valve. 

 " 2/i. Interior of a fragment of a right valve, from the Belly Kiver, 

 which shews the cartilage pits nf the anterior end of the 

 hinge line. 



MdDIOLA (BkACIIYDoNTEs) ULCHliTil.MA (pagC 37). 



Figure 3. Lateral view of a right valve witli the test jireserved. from the 

 St. Mary Kiver. Considerably enlarged. 

 " 3<(. Similar view of a cast of the interior of the closed vaUes of the 

 shell iif a larger and ajiparently more adult individual, frcun 

 the same locality. Also considerably enlarged. 



