634 
Figs. 27 and 28. Temnochetlus (Naut.) subtuberculatum (sp. Sandberger), 
Hyatt; Loc , Wissenbach; Coll. Mus Comp. Zodlogy ; Devonian. 
Fig. 27, side view of ana-, meta- and paranepionic and perhaps beginning of 
ananeanic substages before the whorls touch. It will be observed that the apex 
is not enveloped even in this closely coiled form and that the dorsal furrow is not 
present at the end of the volution, Fig 27, which is given in the section Fig. 28. 
Figs. 29-31. Apheleceras (Naut.) mutadile (sp. D’Orb.), Hyatt: Loc., Car- 
boniferous; after D’Orbigny, Pal. Universelle, Pl. \xxxvili, Figs. 1, 2 and 4. 
Show the free apex and moulding of the dorsum to fit the hollow venter of this 
species. Fig. 31 shows the surface of the shell of earlier substages. 
Fig. 32. Metacoceras cavatiformis (same specimen as Figs. 16-19, p. 496 of 
this paper) showing the beginning of the impressed zone at contact with the apex. 
Fig. 33. Cewlogasteroceras canaliculatum, Hyatt; Loc., Edmondson Co., Ky.; 
Mu:. Comp. Zoél.; Carboniferous. A section across the meta- and paranepionic 
volution showing the large umbilical perforation, comparatively slow increase in 
size of the first whorl and presence of a dorsal furrow in the paranepionic sub- 
stage. | 
