Journal Hafner, M.S. 1977 5.5 km. S, 13 km. E Amecameca, 3680m., Mexico, Mexico 5 August (cont) somewhat larger and more densely furred than those from Volcan Toluca. It was soon raining and very cold. 2030 we made our final check of the toaplines for the night. (The traps were then to remain out over night) I used the lantern, but was nevertheless easily disoriented as I stumbled through the fog and wind to find my sets. 2100 Drove down the mountain to reach warmer country. Slept well just outside Amecameca. 5.5 km. S, 13. km. E Amecameca, 3680m., Mexico, Mexico. 6 August 0630 awoke, drove back up to Volcan Popocatepetl. A very chilly, windy morning. Checked traps: Total Results: 18 Thomomys umbrinus (3 alive). We took tissue and blood then departed this locality. We drove S on Hwy 115 to Cuautla, where we had breakfast. We then turned east on Hwy 160 to Izucar de Mataamoros, then S on Hwy 190. We were continually losing elevation as we