Journ. Mar. Biol. Assoc , J'ol. VIII. 



Fio. 1. 



Plate X. 



M. 62b, 8. 25 W. Edd., 46-4 miles. 



Decomposed black flint. 

 Ordinary ligJd. x 97J. 



Fig. 2. 



M. 62b. 8. 25 W. Edd., 46-4 miles, 



Decomposeil black fliut, the lower half of plate rejn'esents portion of slide 

 treated with acid. 



Crossed nicols. x 97|. 

 Shell fragments dissolved away 

 from lower half. 



Ordinary light, x 97J. 



Shell fragments dissolved away 



from lower half. 



To face p. 1;13. 



