Head drawings: genus Gyalopion(Serpentes: Colubridae) - compiled by Van Wallach Home

Gyalopion canum (from Cope 1900)
Gyalopion canum (from Powell & al. 2019)
Gyalopion canum (from Schmidt & Davis 1941)
Gyalopion canum (from Stebbins 1954)
Gyalopion canum (from Lemos-Espinal & al. 2015)
Gyalopion canum (from Lemos-Espinal & al. 2015)
Gyalopion canum (from Smith 1941A)
Gyalopion canum (from Smith 1941A)
Gyalopion canum (from Smith 1941A)
Gyalopion quadrangulare (from Günther 1885-1902)
Gyalopion quadrangulare (from Smith 1941A)
Gyalopion quadrangulare (from Günther 1885-1902)
Gyalopion quadrangulare (from Smith 1941A)
Gyalopion quadrangulare (from Smith 1941A)
Gyalopion quadrangulare (from Lemos-Espinal & al. 2015)