A synopsis of Typhlocarcinops Rathbun, 1909 (Crustacea: Decapoda: Brachyura: Pilumnidae), with descriptions of nine new species from the Indo-West Pacific.

The taxonomy of the Indo-West Pacific rhizopine genus Typhlocarcinops Rathbun, 1909 (Pilumnidae) is revised and 22 species are recognised. The identification of these small, soft sediment-dwelling crabs has been difficult because many of the types have never been figured and described to modern standards. The identity of the type species, T. canaliculatus Rathbun, 1909, is clarified and T. gallardoi Serène, 1964, is shown to be its junior synonym. Similarly, T. genkaiae Takeda Miyake, 1972, and T. takedai Ng, 1987, are synonymised with T. decrescens Rathbun, 1914, and T. marginatus Rathbun, 1914, respectively. Nine new species are described: T. robustus, T. hamus, T. raouli, T. atimovatae, T. hadrotes, T. hirtus, T. diminutus, T. kanashi and T. lapillus. The various species are defined by a suite of carapace, cheliped, third maxilliped, male pleonal and male first gonopod characters. The type and only known specimen of the poorly known rhizopine Paraselwynia ursina Tesch, 1918, which is superficially similar to Typhlocarcinops, is figured and compared. A key to all known species of Typhlocarcinops is provided.