PLATE XXII. 



PEODUCTUS INTEBBUPTUS, Sowerby (?). (Page 172.) 

 FIG. 



1. Ventral valve, lying obliquely in the matrix, showing the ribs arid the interrupting grooves and 



ridges in the posterior parts, x 3. Pilton. Porter Collection. 



2. Dorsal ? valve, somewhat worn, showing the transverse ridges over the whole surface, x 2. 



Fremington. Porter Collection. 

 3.|Portion of a crushed specimen, showing ornament, X 8. Pilton. Porter Collection. 



CHONETES HABDBENSIS, Phillips, sp. (Page 177.) 



4. Cast of dorsal valve, showing the areas of the dorsal and ventral valves, and the divaricating ribs, 



x 3. Saunton Hotel. My Collection. 



CHONETES MABGABITACEA, Whidborne. (Page 179.) 



5. Ventral valve, showing the shape and the simple ribs, x 3. 5 o. Portion of surface, showing the 



shape of the ribs and the transverse ornament, x 10. Eoborough. Porter Collection. 



6. Another specimen, much crushed, showing two of the hinge-spines, x 3. Braunton. Museum of 



Practical Geology. 



CHONETES ILLINOISENSIS, Worthen(?}. (Page 179.) 



7. Dorsal valve, showing the crowded divaricating and slightly waved striae and the slight genicula- 



tion, x 3. Fremiugton (?). Porter Collection. 



8. Ventral valve, much crushed, showing one of the long oblique hinge-spines, x 3. Fremington (?). 



Porter Collection. 



CBANIELLA INSECUBA, n. sp. (Page 180.) 



9. Cast of dorsal valve, showing the apex, the casts of the muscle-scars, and the ornament assumed 



from the organism to which the other valve was attached, x 2. Pilton Beds. Barnstaple 

 Athenaeum. 



CBANIA? BICTA, n. sp. (Page 182.) 



10. Ventral valve, showing the divaricator, the occlusor, and the ventral adjuster (?) muscle-scars, x 3. 



10 a. Portion, showing the minutely tuberculated inner surface, x 10. Pilton. Porter 

 Collection. 



DISCINA NITIDA, Phillips, sp. (Page 183.) 



11. Upper valve, which is a cast in the central part, but retains the surface near the margins, the 



front part of which is covered by matrix, x f- . 11 a. Lateral view, x -f. Saunton Hotel. 

 Miss Partridge's Collection. 



12. Lower valve, x f . West Angle Bay, Pembrokeshire. Museum of Practical Geology. 



LINGULA SQUAMIFOBMIS, Phillips. (Page 183.) 



13. Dorsal valve, showing the radiations on the surface, x 2. Saunton Hotel. Miss Partridge's 



Collection. 



FENESTELLA PLEBEIA, M'Coy. (Page 185.) 



14. Part of a large frond. 14 a. A fenestrule, showing the non- poriferous surface, x 20. 14 I. A 



fenestrule, which is a natural section, showing five or six cells between the dissepiments, x 20. 

 Snapper Quarry. Hamling Collection. 



15. Fragment of a frond. 15 a. Portion, showing a nodulated surface, and the section of some cells, 



X 20. Ironpost. My Collection. 



FENESTELLA ? UMBBOSA, n. sp. (Page 186.) 



16. Wax impression of the natural cast of a frond. 16 a. A portion of the surface showing the blunt 



central keel, the shape of the fenestrules, and three or four cell-mouths to a fenestrule, x 20. 

 Koborough. Barnstaple Athenaeum. 



