E.L. Karlstam 1954 Budger Jones (26) May 13 Stoneman meadow, 4000 ft., Yosemite Valley, Mariposa Cr., Calif. pond surface, all evidence points to the fact that the oil now in and in Pond A is not led to the trodgers. A sketch of the oil sum at the SE end of the pond shows that Hydra trods are even under- neath it at its edges although they are few in number. Water level in Pond A is down to original level (when I placed max-min out April 9, 1954), some of the smaller ponds are fast drying up. Hydra have lived in pools not more than 1 x 2 x 1-2" deep located on a clay footpath. Pool B3 (long ditch parallel to footpath) shows much higher trodger mortality. Oil forms scum over nearly all of pond surface. Few Budger and Hydra present - single taken. Water temp, 1" below surface 2' from edge 29.50 C. 1:40 P.M. (D.S.T.) air temp 18 olive grass (ladder slotted) 24.50 C. Night check some locality. Found an D.O.R. food on main road through meadow about 50 yards N by NE of Pond A. Dead at least 24 hours, probably longer. Appears to be o>, large adult. 11:50 P.M. (D.S) young ? adult found edge of footpath passing through SE meadow. Closed pool about 20 yards N of spot. length (body) 6-7 mm. This mind for bright velated stage than after 2 o>> found Bart. Center meadow earlier tonight. washed + released her (RF2-2ep loth sheet) chloral 10.20 C., air 1" above wet gross in which animal found 9.50 C.