PLATE I. 



Fig. 1. — Piaaa iiiiitira. The type of M'Coy's Pliiiia spatida preserved in the 

 AVoodwardian Museum, Cambridge. Incomplete in front. From the Carboniferous 

 Limestone of Derbyshire. (Page 4.) 



Fig. 2. — Pinna mutica. A left valve showing the posterior adductor muscle- 

 scar. Same Collection. (Page 4.) 



Fig. 3. — Pinna inufica. The fragment on which M'Coy founded the species 

 from Kilbride, Ballycastle, co. Mayo. In the Griffith Collection, Museum of 

 Science and Art, Dublin. (Page 4.) 



Fig. 4. — Piu,)ia mnfica. Portion of a left valve, showing the rolled hinge- 

 edge. From Cavedale, Castleton. My Collection. (Page 4.) 



Fig. 5. — Pinna mntica. A right valve from the Carboniferous Limestone of 

 Cavedale, Castleton. My Collection. (Page 4.) 



Fig. 6. — Phina rnntica. A fine but compressed specimen from the Calciferous 

 Sandstone series of Griencartholm, Dumfries. My Collection. (Page 4.) 



Fig. 7. — Lciopfrria s([iiaino><a. A right valve from the Carboniferous Lime- 

 stone of Castleton, Derbyshire, with 7 n, a view from above. My Collection. 

 (Page 16.) 



Fig. 8. — Leiopfpria squam<mi. The type of Acicnla gibhosa, M'Coy, from 

 the Upper Limestone, Manor Hamilton, co. Leitrim. In the Griffith Collection, 

 Museum of Science and Art, Dublin. (Page 16.) 



Fig. 0. — Leioptpria. sipiamosa. The type of Phillips's (JcrvilJid sqnanioxa, 

 preserved in the Gilbertson Collection, Natural History Museum, South Ken- 

 sington. (Page 16.) 



Fig. 10. — Lciopfpvia suptamosa. A left valve from the Carboniferous Lime- 

 stone of Castleton, Derbyshire. My Collection. (Page 16.) 



