PLATE LXII. 



Page. 

 Fig. 1. Orthis remnicha 451 



1. Rather strongly costate dorsal valve, x 2. 

 la. Finely costate ventral valve, x 3. 



16. Finely costate dorsal valve on same bit of rock as fig. la. x 3. 

 lc. Strongly costate ventral and dorsal valves, x 3. 



Id. Dorsal and ventral valves, showing fine radiating stride on cost.-e. x 3. 

 Fig. 2. Acrotreta gemma 449 



2. Summit view of ventral valve, x 6. 

 2a. Posterior view of ventral valve, x 6. 

 26. Side view of ventral valve. 



2c. Summit view of cast of interior of ventral valve, x 6. 



2d. Dorsal valve, x i. 



2e. Interior of dorsal valve, x 6. 



472 



