8 
N. W. ARCHBOLD 
Fig. 4. A-E, Taeniothaeruscf. irwinensis Coleman. A, B, CPC 28042, incomplete external mould of dorsal valve, 
x 1, portion enlarged, x 3.5. C, D, CPC 28043, incomplete ventral valve in ventral and posterior views, x 1. E, 
CPC 28044, incomplete external mould of dorsal valve, x 1. F, G, Cancrinella irwinensis Archbold. F, CPC 
28045, incomplete natural cast of juvenile ventral valve, x 2.5. G, CPC 19918, natural cast of ventral valve, x 
2 . . 
