Fig. 110. Dorsoventral cross section through a in Scaphites Of The ''Nodosus Group'' From The Upper Cretaceous (Campanian) Of The Western Interior Of North America

Fig. 110. Dorsoventral cross section through a small microconch of Hoploscaphites brevis (Meek, 1876), transitional in morphology to macroconch, USNM 536254, USGS Mesozoic loc. D12203, Baculites compressus Zone, Pierre Shale, Pennington County, South Dakota. The plane of the cross section approximately coincides with the line of maximum length. A. Camera lucida of cross section of the adult shell. The stippled area demarcates the mature body chamber. B. Camera lucida of cross section of the inner whorls. C. Photo of cross section of the inner whorls. Measurements are listed in appendix 2, table 5.