Peterson 1935. contents fixed in Bouin's fluid. Blood smear made from heart blood. Large beaver found to have red reematode worms about 12-15 mm. long in stomach. Many reematodes found in wall of cecum and upper portion of large intestine. Both fixed in Bouin's fluid. Peculiar glandular development on wall of portion of stomach noted. Little beaver with no parasites. Sample of cecal contents & porcupine and beaver fixed in Bouin's. Blood smear made from liver blood of large beaver. 100 traps set in slopes + depressions covered with sage brush. July 8. Catch included 1 Microdipodops megacephalus, 2 Eutamias m. sculptator, and 7 Peromyscus m. sonoriensis. Skins prepared of Microdipodops megacephalus and one Peromyscus m. sonoriensis. Skins so far prepared by all 4 members of the expedition segregated + compared - good and bad points noted. Microdipodops megacephalus and one Peromyscus m. sonoriensis examined for internal parasites. None found. Heart blood and cecal smear made from each one. Mites, ticks, fleas, lice picked off various specimens and preserved. about 40 mouse traps set on gravelly flat along