Thalassocalyce is a genus of ctenophore, or comb jellies, known from the California Coast, Gulf of Mexico, and west north Atlantic.

[2][5] Thalassocalycid morphology is unique within the Ctenophora, sharing certain similarities to both cydippid (i.e. canal structure) and lobates, and characterized by absence of auricles and muscular lobes.

While morphologically and structurally distinct from the oral lobes of lobate ctenophores,[2] the thin thalassocalycid bell is functionally analogous as mechanism for prey-capture.

When fully expanded, the body forms a hemispherical bell, but a bi-radial (“two-globe”) morphology is apparent when the organisms is partially contracted.

[3] Several lobate ctenophores, (e.g. Leucothea multicornis) pass through larval stages that are ‘medusiform,’ but the retention of a medusoid-like bauplan in adults is unique to Thalassocalyce inconstans.