PLATE XI. 



Fig. 1. — Carbonicola obtusa. The hinge-plates of the shell figured on PI. VII, fig. 16, showing a 

 striated pit in the right valve posterior, and in the left anterior, to the cardinal tooth. (Page 61.) 



Fig. 2. — Carbonicola obtusa. Cockshead Eock, Hulme Colliery, Adderley Green, North Stafford- 

 shire. Transverse section, showing a cavity between the hinge-plates, in which possibly was lodged an 

 internal ligament or cartilage. The section is just posterior to the highest point of the umbones. 

 My Collection. (Page 43.) 



Figs. 3 and 4. — Carbonicola angulata. Two pyritised examples from the Low Bottom Bed. 

 Fulledge, Burnley. In the Collection of Mr. George Wild. (Page 75.) 



Fig. 5. — Carbonicola angulata. From same locality, a larger specimen. In the Collection of 

 Mr. John Ward, F.G.S., of Longton. (Page 75.) 



Figs. 6 and 7. — Carbonicola similis. Two typical specimens from the Brooch Coal Series, Dudley. 

 My Collection. (Page 76.) 



Fig. la. — Carbonicola similis. Fig. 7 viewed from above, showing the hollow character of the 

 dorsal slope. 



Fig. 8. — Carbonicola similis. Cast showing muscle-scars and pallial line. Springhill Colliery, 

 Ayrshire. In the Collection of Mr. Beveridge. (Page 76.) 



Fig. 8 a. — The same viewed from above, showing the accessory pedal scars. 



Figs. 9 — 13. — Carbonicola similis. A series from the Brooch Coal-beds, Dudley, showing the 

 change in shape of the posterior end by age. Presented to me by Mr. Wm. Madeley. My Collection. 



Figs. 10 a, 11a. — Carbonicola similis. Figs. 10 and 11 viewed from above, showing external 

 ligament and general shape of the superior surface. (Page 76.) 



Figs. 14, 14 a. — Carbonicola nucularis. Two views of a very testiferous pyritised specimen with 

 much-wrinkled periostracum from the horizon of the Banbury, ? Hard Mine, Talk-o'-th'-Hill, North 

 Staffordshire. My Collection. (Page 63.) 



Fig. 15. — Carbonicola similis. Brooch Coal Series, Dudley. To show the hinge-plate of the right 

 valve. My Collection. (Page 76.) 



Fig. 16, 16 a. — Carbonicola nucularis. Two views of a testiferous specimen from the spoil bank of 

 a disused colliery at the west foot of Mow Cop, North Staffordshire, which from the fossil contents 

 I believe to be about the horizon of the Hard Mine, showing much-wrinkled periostracum. My 

 Collection. (Page 63.) 



Figs. 17 — 23, 25 — 27. Carbonicola similis. A series from a thin bed above the Cockshead Kock, 

 Hulme Colliery, Adderley Green, North Staffordshire, showing variations in shape often due to crushing. 

 My Collection. (Page 76.) 



Fig. 24. — Carbonicola cuneiformis. The roof of the Hard Mine Coal, Bucknall. My Collection. 

 (Page 78.) 



Fig. 24 a. — Carbonicola cuneiformis, viewed from above. 



Figs. 28, 29. — Carbonicola antiqua. From the Calciferous Sandstone Series, Kilminning, Fife. 

 My Collection. (Page 79.) 



Fig. 28a. — Carbonicola antiqua. An imperfect view of the hinge-plate of fig. 28. 



Fig. 30. — Carbonicola antiqua. This is not a cast, but the shell has been worn smooth by wave 

 action. From the same bed. My Collection. (Page 79.) 



Fig. 31. — Carbonicola aquilina. A very large and fine example from the roof of the Hard Mine 

 Coal, Adderley Green Colliery, Longton. My Collection. (Page 69.) 



Figs. 32 and 33. — Carbonicola aquilina, to show curious circular perforations. Collection of 

 Mr. John Ward, F.G.S., Longton. (Page 74.) 



