Madagasikara johnsoni

Madagasikara johnsoni is a species of tropical freshwater snail with a gill and an operculum, an aquatic gastropod mollusc in the family Pachychilidae.

[2] The most detailed version of the type locality is that of the Kamoro River drainage in Mahajanga Province, north-west Madagascar.

[1] The ribs are six in number on the upper whorls and rounded; the two above are much more slender than the four beneath; the uppermost borders the suture; the next lies in the concavity at the top of the whorls; and the rest surround the slight convexity, and are three times as broad as the sulci separating them.

[1] All the whorls, with the exception of the last four, are coronated at the slight angle below the excavation with very short, hollow, oblique spinules.

[1] Columellar margin is thickened, free, arcuate, reflexed, ending in a distinct basal sinus.