PLATE XVII. 



Fig. 1. — Aviculopeden subconoidens. A right valve. From Knockhill, Fife. Marked as one of 

 E. Etheridge's types. In the Collection of the Geological Survey of Scotland. (Page 77.) 



Figs. 2, 3. — Aviculopeden subconoidens. Two left valves. Also marked as types. Same locality and 

 Collection. (Page 77.) 



Fig. 4. — Aviculopeden subconoidens. A right valve. Same locality. My Collection. (Page 77.) 



Fig. 5. — Aviculopeden sribconoideus. A left valve, full size. Same locality and Collection. 

 (Page 77.) 



Fig. 6. — Aviculopeden gentilis. A left valve. ? The type of Sowerby's Pecten gentilis. From the 

 Pennystone Ironstone, Coalbrookdale. Preserved in the Natural History Museum, South Kensington. 

 (Page 86.) 



Fig. 7. — Aviculopeden gentilis. A right valve. From beds below the Third Grit, Congleton Edge 

 Cheshire. My Collection. (Page 86.) 



Figs. 8, 9. — Aviculopeden gentilis. Two left valves. Same locality and Collection. (Page 86.) 



Fig. 10. — Aviculopeden gentilis. A right valve. Same locality and Collection. (Page 86.) 



Figs. 11, 12. — Pseudamusium sublobatum. Two right valves, showing colour-bands. From Park 

 Hill, Derbyshire. Figured by E. Etheridge, jun. In the Museum of the Geological Survey, Jermyn 

 Street. (Page 110.) 



Figs. 13, 14. — Pseudamusium sublobatum. Two left valves, showing colour-bands. Figured by 

 E. Etheridge, jun. Same locality and Collection. (Page 110.) 



Fig. 15. — Pterinopeden cyclopterus. — Phillips's type. Preserved in the Natural History Museum, 

 South Kensington. (Page 64.) 



Fig. 16. — Pterinopeden cyclopterus. A young example from Little Island, co. Cork. In the 

 Collection of Mr. J. Wright. (Page 64.) 



Figs. 17, 18. — Pterinopeden cyclopterus. The left and right valves of the same shell; the latter 

 imperfect. Same locality and Collection. (Page 64.) 



Fig. 19. — Pterinopeden cyclopterus. A left valve. Same locality and Collection. (Page 64.) 



Fig. 20. —Pterinopeden meleagrinoides. A left valve. From Castleton. My Collection. (Page 62.) 



Fig. 21. — Pterinopeden meleagrinoides. A left valve. Same locality and Collection. (Page 62.) 



Fig. 22. — Pterinopeden meleagrinoides. A left valve. From Thorpe Cloud. My Collection. 

 (Page 62.) 



Fig. 23. — Pterinopeden meleagrinoides. A right valve. From Castleton. My Collection. 

 (Page 62.) 



Figs. 24, 25. — Aviculopeden Carrolli. Two left valves. From Little Island. In the Collection of 

 Mr. J. Wright. (Page 97.) 



Fig. 26. — Aviculopeden Carrolli. A left valve. From Castleton, Derbyshire. Showing broad, 

 radiating colour-bands. My Collection. (Page 97.) 



Fig. 27. — Aviculopeden Carrolli. A right valve ; a cast. From Caherass, co. Limerick. In the 

 Collection of the Geological Survey of Ireland. (Page 97.) 



Fig. 28. — Aviculopeden fallax. The cast of a right valve. From Doohylebeg, co. Limerick. Same 

 Collection. (Page 76.) 



Fig. 29. — Aviculopeden fallax. A right valve. From Millicent, Kildare. In the Woodwardiau 

 Museum, Cambridge. (Page 76.) 



Fig. 30.— Aviculopeden fallax. A left valve. From Gortnagrour, co. Limerick. In the Collection 

 of the Geological Survey of Ireland. (Page 76.) 



