EXPLANATION OF PLATES. 171 



Fig. 10, Cijthere {Ba'trdla) var. i^homblca., Joaes : left valve. 11, Inside of the 



right valve of another specimen. 

 12rt, pltbeia^ Reuss : var. small individual, or diminutive 



rhombical form; left valve — 126, edge-view. 

 13a, var. grandis, Jones : right valve cast — 136, 



edge-view. 

 14a, Cythere (Bairdia) ampla^ Reuss: showing cast of the right valve, and 



edge of the left — 146, edge-view — 14c, end-view. 



15, Cythere {Bairdia) gracilis^ M'Coy: cast, showmg the outline of the 



right-valve. 



16, Cythere (Bairdia) acuta, Jones : left valve. 



17, Cythere {Bairdia) pJebeia, Reuss., var. caudata, Kirkby: right valve, 



Sunderland. 18a, another specimen, left valve— 186, profile— 18c, 

 end-view. 



19a, Cythere {Bairdia) a7npla, 'Renss : closed carapace, with right valve up- 

 wards, Yorkshire— 196, the same, left valve upwards — 19c, ventral 

 aspect— ]9fZ, dorsal aspect— 19e, end-view— 19/', punctation, mag- 

 nified 50 diam. 



20a, Cythere Tyronica, Jones : right valve, Ireland — 206, profile. 



21a, Cythere Richteriana, Jones: left valve, German}' — 216, profile— 21c", 

 end-view. 



22a, Cythere amputata, Kirkby: cast of carapace, with left valve upwards, 

 Sunderland — 226, ventral aspect — 22c, dorsal aspect— 22c?, anterior 

 aspect. 



23a, Cythere subreniformis, Kirkby: carapace, with right valve upwards, 

 Sunderland— 236, ventral aspect— 23c, dorsal aspect— 23(7, end-view. 



24a, Cythere Jonesiana, Kirkby: carapace, with right valve upwards, Sun- 

 derland— 246, ventral aspect— 24c, dorsal aspect— 24af, end-view. 



25a, smaller variety ; carapace, with right valve 



upwards, Sunderland— 256, ventral asptct— 25c, dorsal aspect— 

 25c?, end-view. 



