Journal Hafner, M.S. 1977 Ventura, 1680 m., San Luis Potosí, México. 25 July (cont) About one-half of the gophers captured were totally melanistic; the others were deep brown. The melanistic individuals seemed to be rather clumped in distribution (see map). We drove into Villa Hidalgo for a nice 18 peso dinner. We then returned to Ventura and slept on a side road near the Quarry, awake occasionally at night for passing trains. Ventura, 1680 m., San Luis Potosí, México. 26 July 0545 awoke and drove to check gopher sets that had been left out over night. Final capture results: 22 Thomomys umbrinus (2 live) (9 of which are melanistic) We finished taking blood and tissue and at 0900 departed this locality. We drove SW SE on Hwy 57, through San Luis Potosí, (where we got food for the live specimens), then on westwardly on Hwy 70 to a point [illegible] along the highway 11 km. N, 12 km. E Arriaga. This is the area where we had spotted the diggings of a few gophers yesterday as we passed through. We immediately set out 5 sets of live gopher traps, and placed the prepared specimens in the hot sun to dry. After about an hour