J. Rodgers -1943 Eumeces shiltonianus Feb. 19, 1943 '1/4 mi. E Bald Peak, Contra Costa Co., Calif. We (Walt Dalquest and) collected today in a place where we had not collected since last April day 1944. Walt found 6 skinks, none under rocks that had been turned over before. I found 7, and two were under rocks that had been turned over before; they were both in little hollows they had made under the rock and there was evidence that they had dug under from the edge of the rock. Three others of mine were also in hollows under rocks and two were very active; one ran from under a rock when I turned it and the other was running along thru the short green grass when I first saw it. I may have scared it out from under a rock without noticing it. I saw the bright blue tail of another disappear down an old burrow as I turned over a rock, but could not get it. The grass under the tightest (flattest closest to the ground) rocks that were turned over last year has completely dried out and is pretty thoroughly decayed. Since the skinks have to dig the surface layer of ground to get under rocks it seems safe to assume that it is necessary for the grass to nearly completely decay before the rock is useful to the skink as a shelter again after it has been overturned onto grass-covered ground. Generally speaking then, they can begin to use the rocks after 10 to 12 months from the time they were overturned,