PLATE 25 



Pterinea cf. fasciculata Goldfuss 



Page 102 



i, 2 Casts of the hinge in left valves, x 2. The umbones have been 



removed to expose the ligament surface and the dentition 

 3, 4 Internal casts of left valves 

 5, 6 Exteriors of left valves showing sculpture 

 7 Internal cast of a right valve 

 Locality. Presque Isle stream 



Pteronitella peninsulae Clarke 



Page 105 



8, 9 Internal casts of right valves with clearly defined muscle and pallial 



scars 

 Locality. Presque Isle stream 



Pterinea brisa Clarke 



Page 104 



10 A right valve showing character of exterior 

 Locality. Edmunds Hill 



Pterinea chapmani Clarke 



Page 103 



1 1 A left valve 



Locality. Edmunds Hill 



Myalina pterinaeoides Clarke 



{See plate 26) 

 Page 106 



12 Enlargement of a portion of the exterior surface 



13, 14 Internal cast and internal surface of a right valve 



15 Internal cast of right valve 



1 6 Exterior of a right valve 



17, 1 8 Internal casts of left valves 



Locality. Presque Isle stream 



216 



