PLATE XVI. 



Fig. 1. — Aviculopecten nobilis. A left valve. From the Carboniferous Limestone of Settle. Wood- 

 Avardian Museum, Cambridge. (Page 90.) 



Fig. 2. — Aviculopecten nobilis. A right valve. Same locality and Collection. (Page 90.) 



Fig. 3. — Aviculopecten nobilis. A left valve. Same locality and Collection. (Page 90.) 



Fig. 4. — Aviculopecten nobilis. A left valve. From Settle. Same locality and Collection. (Page 

 90.) 



Figs. 5, 6. — Aviculopecten nobilis. Two left valves. Same locality and Collection. (Page 90.) 



Fig. 7. — Aviculopecten stellaris. A left valve, the type specimen. In the Gilbertson Collection, 

 Natural History Museum, South Kensington. (Page 88.) 



Fig. 8. — Aviculopecten stellaris. A left valve. From Castleton. My Collection. (Page 88.) 



Figs. 9, 10. — Aviculopecten stellaris. Left valves. Same locality and Collection. (Page 88.) 



Fig. 11. — Aviculopecten stellaris. A right valve. From Little Island, co. Cork. Mr. J. Wright's 

 Collection. (Page 88.) 



Fig. 12.— Aviculopecten incrassatus. A left valve. From the Carboniferous Limestone of Cork. 

 Mr. J. Wright's Collection. (Page 89.) 



Fig. 13. — Aviculopecten incrassatus. A left valve. Siim locality and Collection. (Page 89.) 



Fig. 14.— Aviculopecten incrassatus. A left valve. From Little Island, co. Cork. Same locality 

 and Collection. (Page 89.) 



Fig. 15. — Aviculopecten incrassatus. The type specimen, a left valve. From Lisnapaste, co. 

 Donegal. In the Griffith Collection, Museum of Science and Art, Dublin. (Page 89.) 



Fig. 16. — Pseudamusium fibrillosum. A right valve, external cast. Coal Measures, River Tame, 

 Ashton. Probably the type. Museum of the Geological Survey, Jermyn Street. (Page 106.) 



Figs. 17 — 19.— Pseudamusiuni fibrillosum. Three left valves. Same locality and Collection. (Page 

 106.) 



Fig. 20. — Pseudamusiuni fibrillosum. Both valves from Slieve Carna, co. Mayo. In the Collection 

 of the Geological Survey of Ireland. (Page 106.) 



Figs. 21, 22. — Pseudamusium fibrillosum. Two right valves. From River Ribble, near Little 

 Dinckly Hall. Pendleside Series. My Collection. (Page 106.) 



Fig. 23. — Pseudamusium auriculatum. A right valve. From Millicent, Kildare. In the Wood- 

 wardiau Museum, Cambridge. (Page 108.) 



Fig. 24. — Pseudamusium auriculatum. Distorted by shearing. The type of Lima Icevigata, 

 M'Coy. In the Griffith Collection, Science and Art Museum, Dublin. (Page 109.) 



Figs. 25, 26. — Pseudamusium auriculatum. The left and right valves of a shell. From Knocksouna, 

 co. Limerick. In the Collection of the Geological Survey, Dublin. (Page 108.) 



Fig. 27. — Pseudamusium auriculatum. A left valve. Same Collection. (Page 108.) 



Fig. 28. — Aviculopecten Sedgwichi. A left valve. From Little Island, co. Cork. Mr. J. Wright's 

 Collection. (Page 101.) 



Fig. 29. — Aviculopecten SedgwicM. A left valve. From Narrowdale, Staffordshire. My Collection. 

 (Page 101.) 



Figs. 30—32. — Aviculopecten Sedgwiclci. Three views of a bivalved example showing the flattening 

 of the right valve. From Little Island, co. Cork. Mr. J. Wright's Collection. (Page 101.) 



Fig. 33. — Aviculopecten Sedgwicki. A left valve. Same locality and Collection. (Page 101.) 



