PLATE 41 



Orthothetes (Schuchertella) becraftensis Clarke 



Pages 199, 238 



I Interior of a dorsal valve, a silica replacement, showing the simple sur- 

 face plications x 2 

 2, 4, 5 Views of the ventral valve 

 3 Dorsal view of a iiattened specimen 

 6, 7 Silica replacement of a ventral valve, x 2 

 8 Internal cast of a ventral valve 



Grande Grevc limestone ; division 2. Grande Greve 



Orthothetes (Schuchertella) woolworthanus Hall mut. gaspensis nov. 



Page igg 



9, 10 Interior of dorsal valves 



11 Dorsal aspect of an internal cast, showing muscle scars and pallial 



markings 



12 Internal cast of ventral valve, showing highly developed adductor scars 



13 Interior of dorsal valve, a silica replacement 



Grande Grhve limestone ; divisions i and 2, Grande Greve 



Orthothetes (Schuchertella) woolworthanus Hall 



Page 112 



14 Internal cast of ventral valve 



St Alban beds. Cape Rosier Cove 



Anoplia nucleata Hall 



Page 211 



15 Internal cast of ventral valve enlarged to show the filling of the spine 



tubes crowning the cardinal area, x 10 



16 Interior of a dorsal valve, x 3 



17 Internal cast of ventral valve, x 3 



Grande Greve limestone ; division 2. Grande Greve 



Chonetes billingsi nov. 



Pages 209, 238 



18 Ventral valve, x 2 



1 9 Dorsal view of a specimen, bearing a spine near the cardinal angle, x 2 



334 



