Geoplana gayi Schultze & Müller, 1857 Polycladus is a genus of land planarians from South America, currently comprising a single species, Polycladus gayi, which occurs in the Valdivian Forest, Chile.

It was defined as land planarians with a wide, flat and leaf-like body, having the entire ventral surface ciliated and with mouth and gonopore posteriorly shifted in relation to other land planarians.

The copulatory apparatus has a well-developed permanent penis and the female canal enters the genital antrum ventrally.

[2] In 2023, Polycladus was discovered preying on a black snail, Macrocyclis peruvianus, in the wild.

The specific epithet of the type-species, gayi, commemorates French naturalist Claude Gay.