EXPLANATION OF PLATE XVL 



Fig. 1. lNOCEi!AMUs n.ACCiDus. (Page 17;:!.) 



a. Left valve, uatural size, but some examples are larger. 



h. Interior view of beak and binge, rigbt valve. 

 Fig S, Inoceramcs dimidius. (Page 181.) 



a. Left valve, ordinary natural size. 



b. Rigbt valve. Part of tbe sbell witbont concentric folds, 

 e. Front view, showing convexity of both valves. 



(?. Left valve, showing unusually small concentric folds. 

 Fig. 3. Ikocehamus peoblematicus. (Page 177.) 



a. Left valve. 

 Fig. 4. Lxoceramos Bauabini. (Page 180.) 



a. Left valve. 



