Genus Campascus Leidy, 1879
Diagnosis: shell broadly ovoid, in cross-section circular, ovoid or triangular; neck cylindroid, curved; fundus rounded or with up to three projections; aperture circular, surrounded by a characteristic hyaline collar; composition of the shell is variable. Some species have circular, other amorphous, siliceous scales sometimes mixed with mineral particles, usually not regularly arranged; nucleus ovular.
Type species Campascus cornutus Leidy, 1879.
C. triqueter Penard (1891)
C. minutus Penard (1899)
C. dentatus Edmondson and Kingman (1913)
C. bidens Krascheninnikov (1923)
C. vulgaris Valkanov (1936)
C. interstitialis Golemansky (1981)
C. cyphoderiformis Chardez and Gaspar (1984)
C. simcoei Nicholls (2003).
All are freshwater species, except C. interstitialis, which may be restricted to marine sandy beaches (Golemansky 1992). All are poorly known, except for C. minutus, and C. simcoei.