Oylvie 1942 Ceromycus maniculatus May 21 Cedar Grove, South Fork King R., 4600 ft., Fresno Co., Calif. One Ceromycus maniculatus was found in trap by dead log about 50 ft. from Kings R. A young male specimen, grayish above - wt. 9.2 gmo. Trap was set about 7:30 p.m. the night before. May 22 Another Peromyscus (2) was collected on north side of King R. close by a dead log in marsh grass area. It was collected by Virginia D. Miller. May 23 A female Peromyscus maniculatus was collected about 100 yds. from camp by an old pine trunk. Area around had only a few pines; ground was sparsely covered with thin grass and small low plants; it was mostly covered with pine needles. This female had 3 pairs of well developed mammae. The vagina was large and very pink. A little blood was oozing from the urinary papillae. The trap had caught her well up on the back and not in the pelvic region. When it was dissected the horns of the uterus each contained four distinct swelling, but the embryos were so minute as to be undistinguishable. May 24 A female Peromyscus was collected several hundred yds. on north side of bridge. It was caught by an old upright cedar trunk. Four very slight swellings in each horn of uterus. May 25 A male was caught at the barn behind Ranger's house. May 31 Three Peromyscus maniculatus, 2 very young ones and a mature female. There were no embryos in the female.