Forest, near Pup´yong-ni, 1 (KU); 2 mi. N Chip´o-ri, 2 (KU); 3 mi. NW Chip´o-ri, 4 (KU); 4 mi. N Ch´onan, 1 (KU); 3 mi. S Kumhwa, 1 (KU); 1 mi. SW Naegong-ni, 1 (KU); 4 mi. E Seoul, 1 (KU); 5 mi. E Seoul, 2 (UMMZ); 5 mi. ESE Seoul, 4 (KU); 6 mi. E Seoul, 1 (KU), 4 (UMMZ); 7 mi. ESE Seoul, 1 (KU); 6 mi. NNE Sogwi-ri, Cheju Do, 2 (KU); 5 mi. NE Taejon, 1 (KU).

Remarks.—This common, vagrant species was found on brushy hillsides, near buildings on hills above rice fields, in tall grasses near streams, in rice fields, and along drainage and irrigation ditches. The earliest and latest dates of collection were April 5 and November 7. On the first date mentioned an individual was found in hibernation with five Elaphe rufodorsata and one Agkistrodon halys in an earthen Korean burial mound. The specimen was uncovered by a bulldozer at a depth of about one foot below the surface. We were told that 18 snakes of this species were found in the same place (7 mi. ESE Seoul) the previous winter.

The stomach of each of four individuals contained one Rana nigromaculata. The stomach of another individual contained a R. nigromaculata and remains of a carabid beetle, whereas another contained three small, partially-digested frogs that appeared to be Hyla arborea. P. M. Youngman reported to us that he found a snake of this species that was attempting to swallow a toad, Bufo bufo gargarizans. One of the small individuals from Cheju Do was being eaten by a Zamenis spinalis when found. One specimen was parasitized by three nematodes, Kalicephalus natricis (see Olsen, 1957:208).

Two females of this oviparous species (lengths of body, 680 and 700) collected on May 14 contained nine eggs (18 mm. long), and 13 eggs (15 mm.) respectively; a third (length of body, 610) obtained on June 26 contained 10 eggs that were approximately 18 mm. long. A female (UMMZ 113458, length of body, 710), which was captured on July 10 and kept alive in captivity, laid 11 eggs on August 12 between 9 and 10 in the morning. The weight of nine of these eggs averaged 3.32 (3.0-3.6) grams; the last two eggs deposited were small and weighed only 1.3 and 1.4 grams. The eggs were incubated unsuccessfully. One that was opened on September 14 and another opened on September 26 contained young easily recognized as of this species. In captivity the parent

snake underwent ecdysis on about July 20 and again on August 26.

Our largest female and largest male have respective total lengths of 1013 (840 + 173) and 740 (575 + 165). Our smallest specimens, captured on September 9, measured 215 and 230 mm. in length of body, and probably represent young of the year. The snake found in hibernation on April 5 measured 275 in length of body. The ventrals of 11 males averaged 161.3 (158-171) and those of 14 females, 165.1 (160-170); subcaudals of eight males averaged 69.6 (66-74) and those of 14 females, 61.5 (52-73).

Males seem to have small scales in the anal region that are more strongly keeled than scales elsewhere on the body (the scales catch on finger tips when rubbed in a posteroanterior direction), but males lack small tubercles on the upper and lateral parts of the head as mentioned by Maslin (1950:433). The comments of the same author (op. cit.:434) concerning integumental poison glands in the nuchal region of this species are of interest in view of several reports that we received of swollen extremities resulting from handling snakes of this species.

In using the generic names Rhabdophis and Amphiesma for species formerly placed in the genus Natrix, we follow Malnate (1960), who divided Natrix (auct.) into five distinct genera.

Amphiesma vibakari ruthveni (Van Denburgh)