PLATE XXII. 



Fig. 1. — Cardiomorpha orbicularis. A full-grown example from the Carbo- 

 niferous Limestone of Belgium. In the Collection of the British Museum (Natural 

 History), South Kensington. (Page 264.) 



Fig. 2. — Cardiomorpha communis. A specimen from the Carboniferous Lime- 

 stone of St. Dooghlas, co. Dublin. My Collection. (Page 262.) 



Fig. 3. — Cardiomorpha orbicularis, showing part of the hinge-plate of a left 

 valve from the Carboniferous Limestone of Belgium. In the Collection of the 

 British Museum (Natural History), South Kensington. (Page 264.) 



Fig. 4. — Cardiomorpha orbicularis. A left valve showing the hinge-plate, 

 presented to me by Prof. G. DeWalque from the Carboniferous Limestone of 

 Belgium. (Page 264.) 



Fig. 4 a. — Cardiomorpha orbicularis. The same specimen showing the exterior 

 of the valve. (Page 264.) 



Fig. 5. — Cardiomorpha orbicularis. A complete cast from the topmost bed of 

 the Carboniferous Limestone, Castleton, Derbyshire. My Collection. (Page 

 264.) 



Fig. 5 a. — Cardiomorpha orbicularis. The same specimen viewed from above, 

 showing the grooves left by the impressions of the hinge-plates. 



Fig. 6. — Cardiomorpha orbicularis. The type specimen figured by M'Coy from 

 the Carboniferous Limestone of Derbyshire. In the Woodwardian Museum, 

 Cambridge. (Page 264.) 



Fig. 7. — Cardiomorpha orbicularis. To show the anterior portion of the shell. 

 Viewed from the front. From the Carboniferous Limestone of Settle, Yorkshire. 

 In the Woodwardian Museum, Cambridge. (Page 264.) 



