Image of Streptaxoidea J. E. Gray 1860

Description:

Figure 1.Schematic of shell shapes, last whorl expansion and parietal lamella shape. Terminology of Discartemon apertural dentition in figure B. A–C Shell form and spire A flattened shell with concave spire B depressed-heliciform shell with only slightly convex spire, and C globose-heliciform with conical spire D–F Last whorl expansion D rapidly expanded E intermediately expanded, and F regularly expanded G–I Parietal lamella form G single lamella with straight shape (typical) H single lamella with curved shape (sinuous), and I modified with “Y” shaped lamella.