P. PEARSON 1955 The evening cold (about +4°), windy-blustery. Real altiplano weather, partly cloudy. Sept. 8 Heavy frost, -2°C, the mires in the traps white from frost; The slightly less than 2 bags of traps caught 1 [illegible], 2 Ph. sulphureus, and 4 Ph. darwini. Mice were caught only at stone piles a foot or more deep, preferably 2 or 3 feet deep; not along the windrows of stones piled only a few stones deep, and not away from stone piles. The big sulphurina (possibly daleronops?) was caught late because he was still lump and unforestled. 20 miles S Saloy, 13,000 ft. After the first had been removed and the specimens dried, there seem to be: 4 Ph. darwini, 1 Heffermehl's drolla, 1 Ph. sulphurina or daleronops, and 1 [illegible] with a lobbed tail. This is my first record of mice from the altiplanos. It was certainly in good altiplano country, ½ mile from nearest hut. I started etc. until noon, then drove toward Oruro. Good unpaved road. Much of the way was a mixture of tola trees somewhat like Pampatitina, or like Valley of the Winds at Santa Rosa but tola here shorter. Both Lepidophyllum grandangulare and rigidum present. Passed one set of two-treer dryings at about km 100 (about halfway between Saloy and Oruro), but saw and heard no trees. Some holes plugged golfball-like. Stopped at 4 p.m. on a rolling bunch-grass and tola pampa. Ichn and a coarser bunch grass with a few patches of mothura grass without tola. Almost all the tola is grandangulare, but considerably thorn bush Margynopsis mixed in, plus a few Ephedra and cactiacaetine. No