Hooper, 1937 Inverness, Marin Co., Calif. Mar. 28, it probably dries up in the summer time, since its drainage area is so small. Noted red-tailed hawks (2) and turkey vultures soaring over the canyon. Also saw in the canyon: 1 Western Robin (on telephone line); 1 Soren-tit (and heard several in dense poison oak and Baccharis), 1 late-summer warbler - heard several? in Calif. bay trees. Numerous wood rat houses were noted on SE-facing slope in poison oak and Calif. bay. I set 4-5 mouse traps on SE-facing slope under poison oak, bay, and Baccharis, and 2 rat traps (1 up in bay tree and 1 in nest). Caught: 1 wood rat and 3 meadow mice. At the mouth of the canyon near Bivolar [see U. S. G. S. sheet, edition 1918] in Salicornia about 15 ft. from a chaparral-covered hillside, and ± 10 ft. from a slough on the other side I put out 35 traps. Caught this morning 1 Reithrodontomya and 2 Microtus. In 2 gopher sets made at Bivolar on a grassy hillside I took 1 Thomomys. In the hole in which taken the animal was captured, it was found that the posterior end was facing down the burrow. Yet the hole was well plugged with dirt - it was open.