Figure 61 Mississippian and Pleistocene fossils. (Mississippian, 

 A-D; Pleistocene, E-I). Brachiopods : A I, 2 Orthothetes cren- 

 istria, x24, with lateral view and surface enlargement; B 1, 2 

 Camarotoechia allcgania, x?4, dorsal valve and internal mold of 

 entire specimen. Pelecypods : C Sphenohis aeolus, xl ; D Creni- 

 pecten winchelli, xl ; E Mytilus edulis, x 1 /^; F Mya arenaria, x^4 ; 

 G Yoldia arctica, xl : H Macoma groenlandica (balthica), xl ; 

 I Sa.ricava rugosa, xl. 



