Adult female, bright castaneous with deep castaneous marginal zone. Younger stages yellowish to dark brown. Form oval, hemispherical with narrow margin flattened. As the female grows and bulges from periphery, the margin becomes invisible. Dorsal surface highly chitinous and polished. Younger stages with median longitudinal crest and two transverse ridges which disappears as the female grows, but these become visible again when female grows old and shrinks.