Oligodon saintgironsi spec. nov. can be diagnosed by the combination of 19 dorsal scale rows on the anterior
half to third of the body, 17–18 dorsal scale rows at midbody, a long and strong tail in both sexes, very
long, deeply forked hemipenes, and a blotched dorsal pattern. It differs from all other species of the Oligodon
cyclurus-group by the combination of (1) the length of hemipenes, (2) the relative length of the tail, and (3) in
having only 17 or 18 scale rows at midbody vs. 19, 21, and 23 rows in all others.
Oligodon saintgironsi spec.
nov. differs from O. chinensis which has also 17 MSR by (1) much longer hemipenes (28–29 SC vs. 12–13
SC in O. chinensis), and the dorsal scale row formula, 19–17(18)–15 in O. saintgironsi vs. 17–17–15 in O.
chinensis. Additional comparisons with other species of the Oligodon cyclurus-group and of the genus Oligodon
appear below in the Discussion.