A new species of the genus Caecilia (Caeciliidae) from the western foothills of the Serranía de los Yariguíes in Colombia is described. Caecilia pulchraserrana sp. nov. is similar to C. degenerata and C. corpulenta but differs from these species in having fewer primary annular grooves and a shorter body length. With this new species, the currently recognized species in the genus are increased to 35. Mitochondrial DNA sequences, including newly sequenced terminals representing two additional, previously unanalyzed species, corroborate the phylogenetic position of the new species within Caecilia and the monophyly of the genus. This analysis also included newly sequenced terminals of Epicrionops aff. parkeri (Rhinatrematidae) and trans-Andean Microcaecilia nicefori (Siphonopidae). Evidence was found for the non-monophyly of the family Siphonopidae and the siphonopid genera Microcaecilia and Siphonops. The implications of these results for caecilian systematics are discussed and the status of the trans-Andean populations of Caecilia degenerata is commented upon.
