Range map of subspecies of Ring-necked snake  (Diadophis punctatus).
  D. p. acricus (Key ring-necked snake)  D. p. amabilis (Pacific ring-necked snake)  D. p. arnyi (prairie ring-necked snake)  D. p. dugesii (Dugès' ring-necked snake)  D. p. edwardsii (northern ring-necked snake)  D. p. modestus (San Bernardino ring-necked snake)  D. p. occidentalis (northwestern ring-necked snake)  D. p. pulchellus (coralbelly ring-necked snake)  D. p. punctatus (southern ring-necked snake)  D. p. regalis (regal ring-necked snake)  D. p. similis (San Diego ring-necked snake)  D. p. stictogenys (Mississippi ring-necked snake)  D. p. vandenburgii (Monterey ring-necked snake)  Intergrade zones
Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. 2016. Robert Powell, Roger Conant, Joseph T. Collins. Houghton Mifflin Harcourt, ISBN:978-0544129979
Regal Ring-necked Snake - Diadophis punctatus regalis on California Herps. retrieved on 19 Nov. 2018
Cephas