PLATE VII. 



Fig. 1. — Carbonicola Polrnontensis. The cast of a full-grown example from Omoa, U. C. M. 

 Scotland. Collection of Mr. James Nielson. (Page 58.) 



Fig. 2. — Carbonicola Polrnontensis. Cast showing the pallial line and the adductor muscle scars, 

 from Kirkwood, U. C. M., Scotland. Same Collection. (Page 58.) 



Fig. 3. — Carbonicola Polrnontensis. A cast from Springhill Colliery, Kilmarnock. Collection of 

 Mr. Beveridge. (Page 58.) 



Fig. 3 a. — The same specimen viewed from above. (Page 58.) 



Fig. 4. — Carbonicola Polrnontensis. A cast from the Ell coal, Kilmarnock. Collection of 

 Mr. Smith. (Page 58.) 



Fig. 5. — Carbonicola subconstricta. The original of the figure in Sowerby's ' Min. Conch.,' vol. i, 

 pi. xxxiii, fig. 1. In the Sowerby Collection, Nat. Hist. Mus., South Kensington. (Page 59.) 



Fig. 6. — Carbonicola subconstricta. The original of the figure in Sowerby's ' Min. Conch.,' vol. i, 

 pi. xxxiii, fig. 2. In the same Collection. (Page 59.) 



Fig. 7. — Carbonicola subconstricta. The original of the figure in Sowerby's ' Min. Conch.,' vol. i, 

 pi. xxxiii, fig. 3. In the same Collection. (Page 59.) 



Figs. 8 — 10. — Carbonicola subconstricta. A series from Lowmoor, Bradford, Yorkshire, in the 

 Collection of the Woodwardian Museum, Cambridge. (Page 59.) 



Figs. 11 and 15. — Carbonicola subconstricta. Casts of large forms, showing pallial line and 

 adductor scars from above the thin bed, Buruley. Collection of Mr. George Wild. (Page 59.) 



Figs. 12 and 14. — Carbonicola subconstricta. A series from Lowmoor, Bradford, Yorkshire. 

 My Collection. (Page 59.) 



Fig. 14 a. — A view of fig. 14 seen from above. (Page 59.) 



Fig. 16. — Carbonicola obtusa. From the Lower Coal-measures of North Staffordshire, Whitfield 

 Colliery. The shale has been worked away from these valves since the drawing was made, and the 

 hinge-plates are to be seen on PL XI, fig. 1. My Collection. (Page 61.) 



Figs. 17 and 18. — Carbonicola obtusa. Full-sized examples from the Cockshead Rock, Hulme 

 Colliery, Adderley Green. (Page 61.) 



Fig. 18 a. — Fig. 18 seen from above. My Collection. (Page 61.) 



Fig. 19. — Carbonicola obtusa. A specimen from the M. C. M. of Ashton-under-Lyme, in the 

 Collection of the Woodwardian Museum, Cambridge. (Page 61.) 



Fig. 19 a. — Carbonicola obtusa. The same specimen, viewed from above, showing ? eroded 

 umbones and the wide and excavated lunule. (Page 61.) 



Figs. 20 — 23. — Carbonicola obtusa. A series of young forms from a disused pit on the same 

 horizon as the Hulme Colliery, Dividy Lane. My Collection. (Page 61.) 



Figs. 24 — 29. — Carbonicola nucularis. A series from the roof of the Hard Mine Coal of Adderley 

 Green and Bucknall, showing variations in shape ; all casts. My Collection. (Page 63.) 



Figs. 26 a and 29 a. — Two of the specimens showing the casts of the umbones and hinge-line. 

 (Page 63.) 



Figs. 30 and 31. — Carbonicola nucularis. Two testiferous specimens from beds of the same 

 horizon, Talk-o'-th'-Hill. My Collection. (Page 63.) 



Figs. 32 — 42. — Carbonicola nucularis. A further series from the roof of the Hard Mine Coal, 

 North Staffordshire. My Collection. (Page 63.) The number 39 on the left-hand side should be 36. 



