B. Heske 1982 Journal Tres Rios to San Jose, San Jose Prov., Costa Rica 9 July Arrived back in San Jose ~1300. Overcast + rain again. Checked back in to the ol' Hotel Galilea, went to lunch at the same old restaurant... Spent the afternoon stuffing the weasel + an additional 8 rodents which we won't be karyotyping tomorrow. Duke called Pedro Leon + arranged to use the lab tomorrow. Spent the evening looking through Hall + Kelson and Goodwin's mammals of CR to figure out what the various Oryzomys + Reithrodontomys are - San Jose, San Jose Prov., Costa Rica 20 July Spent the day working in the lab at U. C.R. karyotyping + taking tissues, etc... San Jose, to Canas, Guanacaste Prov., Costa Rica 21 July Left San Jose ~1230. Overcast + scattered showers. Headed NW on Hwy 3 out of town, to Hwy 1. We were delayed during the morning because the bus had been broken into + the tape deck ripped off... At Canas, headed E on Hwy 19. There are several scattered patches of forest in the area, but much of the land has been cleared. A lot of cattle-grazing. I set a line of 60 traps, starting in some secondary and running up a moderate slope (~30-45°) with good forest 8km NE ~190m elevation. of Canas. The forest is composed of broadleaf trees, some large (DBH ~2ft) but many smaller, lots of vines and saplings. Leaf litter floor, but