Isthmura
Isthmura is a genus of salamanders in the family Plethodontidae. They are endemic to Mexico. The genus, which corresponds to the former "Pseudoeurycea bellii species group" and was first described as a subgenus of Pseudoeurycea, was raised to full generic level in 2015 in order to preserve Ixalotriton and Bolitoglossa while avoiding paraphyly of Pseudoeurycea.