The Amkrican Guologist, Vol. XXVIII. 
Plate IV. 
Fig. 7. Concavity and ridge in Medina sandstone. Lockport, N. Y. 
,^^ Looking N. \V. 
Fig. 8. — Ridge in Medina sandstone. Lockport, N, Y. Same as in Fig. 7. 
Fig. 9. — Ordinary ripples on the summit of ttie ridge sliown in Figs. 7 and H. 
The arrows in Figs. 7 and S point to the ripples. 
"Beach Structures in Medina Sandstone."— II. L. Faikcuild. 
