TAB. XX VIII. 



Fig. 



1. Mya truncata, p. 277. 



a, b, from Coralline Crag, at Ramsholt. 



c, var. Uddevallensis. From the Clyde Beds. 



d, e, var. pullus. From the Red Crag 1 , at Butley. 



2. Mya arenaria, p. 279. 



a, b, from the Red Crag, Sutton. 



d, e, var. lata. From the Red Crag, Sutton. 



c, distorted specimen, from the Mammaliferous Crag, Bramerton, 



/, cartilage plate of var, lata. 



