PLATE X. 



ScALDiA ? lONGA, n. sp. (Page 89.) 

 Fig, 



1. Small specimen, retaining surface, with a nearly central umbo, x 2. la. Lateral view. Baggy 



Point, South Cave. Museum of Practical Geology. 



2. Similar specimen of a left valve, x 2. Baggy Point, South Cave. Museum of Practical Geology. 



Mtophoeia inflata, F. a. Homer, sp. (Page 92.) 



3. Cast of left valve, showing the hinge and the anterior muscle-scar. 3 a. Hinge-line, x f. 



Coomhola Grits, County Cork. Museum of Practical Geology. 



4. Specimen of a similar right valve. 4 a. Section. Coomhola Grits, County Cork. Museum of 



Practical Geology. 



Mtophobia deltoidea, Phillips, sp. (Page 93.) 



5. Cast, with a very small umbo. 5 a. Hinge-line, x f . 5 5. Anterior view. Marwood. Museum 



of Practical Geology. 



6. Cast, showing the posterior muscle-scar, x f . 6 a. Anterior view. Marwood. Porter Collec- 



tion. 



7. Specimen, which is possibly the type of Phillips's species. 7 a. Posterior view. Petherwyn. 



Museum of Practical Geology. 



8. Hinge-line of another specimen, showing the posterior muscle-scar, x 4. Marwood. Museum of 



Practical Geology. 



MYOPnoEiA TEiGONA, F. A. BiJmer, sp. (Page 96.) 



9. Large specimen, showing the hinge and the general outline, though probably rather distorted. 



Eichards's Summer House, Croyde Bay. Museum of Practical Geology. 



10. Large cast, much distorted by oblique compression, showing the hinge, the pallial line, and the 



posterior spoon-like process. 10 a. Hinge, x 2, showing the teeth. Barnstaple. Museum of 

 Practical Geology. 



11. Cast of the closed valves, preserving the natural shape, showing the position of the muscle-scars, 



the pallial line, and the spoon-like process, x 2. 11a. Tipper view, showing the umbones and 

 the interlocking of the teeth. Barnstaple. Woodwardian Museum. 



12. Cast of a right valve, showing the anterior muscle-scar and the marginal concavity, which indicates 



the thickness of the shell, x |. Pilton. Porter Collection. 



Ntjcula lineata, Phillips. (Page 97.) 



13. Cast of the closed valves, showing the umbo and the sudden termination of the hinge, x 3. 13 a. 



Lateral view. Upcott. Barnstaple Athenaeum. 



14. Small fragmentary specimen, retaining surface, and showing the ornament, x 5. West of Saunton 



Court. Woodwardian Museum. 



Ctenodonta Newtonii, n. sp. (Page 99.) 



15. Specimen, showing the general form, x 3. Tremington. Barnstaple Athenaeum. 



Peothyeis scalpeata ? n. sp. (Page 88.) 



16. Specimen, so greatly distorted that the umbo assumes a central position, x 3. 16 a. Portion of 



surface, showing the lineations behind the umbo, x 15. Sloly. Barnstaple Athenseuiii. 



17. Another extremely distorted specimen, X 4. 17 a. Portion of lineated surface behind the umbo, 



X 15. South-west of Sloly. Woodwardian Museum. 



