PLATE XXVII 
Figs. 1 A, B. Diestoceras shideleri Foerste. A, lateral view with ven- 
tral side on right. B, ventral view, with siphuncle at base. From the 
basal part of the Whitewater member of the Richmond. Collected by Prof. 
W. H. Shideler, of Miami University. 
Fig. 2. Diestoceras cf. indianense (Miller and Faber). View showing 
the surface striae. From the Saluda member of the Richmond. Collected 
by Prof. W. H. Shideler. 
Figs. 3 A, B. Perigraminoceras laevigatum (McCoy). A, partly ex- 
foliated conch, with surface of shell showing transverse striae. B, part 
of specimen enlarged, showing surface striae. Copied from Foord, Carb. 
Ceph. Ireland, 1897, pi. 5, figs. Id, le. Of Carboniferous age. 
