PLATE 33 



Spirifer arenosus Conrad 



Page 17c, 



I, 3 Ventral valves of small specimen, showing the broad flattened ribs, 



narrow, sharp sulci, plicated sinus and striate surface 

 2 Internal cast of a dorsal valve 

 4-6 Rotund and short hinged ventral valves, in part exposing the 



adductor scars 

 7 Enlargement of surface showing the fine radial striae, x 3 

 8-10 Internal cast of ventral valves 



Grande Grevc limestone. Figures 1,3, 7-10, from divisions i and 2. 

 Grande Greve ; 2, 4-6, from Perce Rock 



Spirifer arenosus Conrad var. unicus Hall 



Page 179 



II A ventral valve with greatly flexed sinus and elevated fold 

 Grande Greve limestone ; division 2. Lehuquet's Cove 



318 



