PLATE XII. 



Figs. 1 and 2. — Anthracomya Adamsii. From the Little Mine Ironstone of 

 Great Fenton. My Collection. (Page 89.) 



Fig. o. — Anthracomya Adamsii. Right valve showing the straight and narrow 

 hinge-line. Same locality. My Collection. (Page 89.) 



Fig. 4. — Anthracomya Adamsii. Cast showing muscle-scars and longitudinal 

 grooves on either side of the hinge-line. My Collection. Same locality. 

 (Page 89.) 



Figs. 5 — 9. — Aibthracomya Adamsii. Same locality. Showing variations in 

 form. My Collection. (Page 89.) 



Fig. 9 a. — Fig. 9 viewed from above. The umbo is not eroded, but is incom- 

 plete. Same locality. My Collection. (Page 89.) 



Fig. 10. — Au-thracomya Adamsii. Showing; distinct colour-bands. Same 

 locality. My Collection. (Page 89.) 



Fig. 11. — Anthracomya Adamsii. Aberrant form. Same locality. My 

 Collection. (Page 89.) 



Fig. 12. — Anthracomya Adamsii. Same locality. My Collection. (Page 89.) 



Figs. 13, 15, 1 6. — Anthracomya Adamsii. Young forms to show stages of 

 growth. Same locality. My Collection. (Page 89.) 



Fig. 14. — Anthracomya Adamsii. Very young form. Burn wood Ironstone, 

 Newchapel. My Collection. (Page 89.) 



Figs. 17,19. — Anthracomya Adamsii. Showing wrinkled periostracum. Little 

 Mine Ironstone, Great Fenton. My Collection. (Page 89.) 



Fig. 18.- — Anthracomya Adamsii. An oval form not full-grown. Same 

 locality. My Collection. (Page 89.) 



