A new species of indotyphlid caecilian amphibian, Hypogeophis montanus sp. nov., is described based on a series of specimens from the Seychelles island of Mahé, collected from two localities in 2013 and 2015. The new species most closely resembles the Seychelles (Mahé) endemic H. brevis in being short (maximum known total length in life ca. 110 mm) and long snouted, but differs by having more vertebrae, a relatively smaller head, and substantially distinct mitochondrial and nuclear gene sequences. Hypogeophis montanus sp. nov. is known from higher elevations (718-731 m) than H. brevis (ca. 350-650 m), and its elevationally restricted distribution on a single small island likely renders it threatened under IUCN Red List criteria. Hypogeophis montanus sp. nov. is the third species of small and long-snouted caecilian reported from the Seychelles. Along with H. brevis and H. pti, H. montanus sp. nov. is among the smallest known species of caecilian and possibly has the smallest global distribution.
Keywords: Amphibia, herpetology, Hypogeophis brevis, Hypogeophis pti, Indian Ocean, Morne Seychellois, systematics, taxonomy.