PLATE 20 



Gyrocy there exaggerata gen. et sp. nov. 

 Fig. 5. Dorsal view of hinge, right valve female, x 150. Paratype, Io. 3128. 

 Chocolate Clays (lower part), sample 24148, Zao River. 



Upper 



Gyrocythere parvicarinata sp. nov. 



Figs, i, 2, 6, 7. Right, left, dorsal and ventral views, carapace male, 

 Io. 4334. Green and Nodular Shales, sample 3407, Rakhi Nala. 



Figs. 3, 4, 8, 12. Right, left, dorsal and ventral views, carapace female, 

 Io. 4281. Green and Nodular Shales, sample 3407, Rakhi Nala. 



X 68. Holotype, 

 X 68. Paratype, 



Gyrocythere grandilaevis sp. nov. 



Figs. 9, 10. Left and right views, carapace male, x 68. Holotype, Io. 4332. Shales with 

 Alabaster, sample 3463, Rakhi Nala. 



Figs, ii, 12. Left and right views, carapace female, x 68. Paratype, Io. 4282. Shales 

 with Alabaster, sample 3463, Rakhi Nala. 



