Fox's mountain meadow snake (Adelophis foxi, meaning "Fox's hidden snake") (Culebra-de vega de Fox in Spanish) is an oviparous colubrid snake described by Douglas A. Rossman and Blaney in 1968. Specimens LSU40793 and LSU40846 were the last recorded specimens, consisting of a male and female collected on the 18th and 19 July 1981 in southwestern Durango, Mexico, most likely around 1.5 miles west of El Salto. While no detailed location information is included in the specimen record, it is noted that the same collector visited this location almost yearly in the late 1960s.