No. Shield Tail snakes, Melanophidium, are not venomous. For future reference, a creature is called "poisonous" when consuming it is harmful. Snakes, spiders, and wasps (and anything else that stings or bites causing harm) are venomous.

Corn snakes are in the colubrid family, the largest family of snakes.

FAMILY: Colubridae

SUBFAMILY: Natricinae

The Uropeltidae are a family of primitive burrowing snakes found in southern India and Sri Lanka. The name is derived from the Greek words ura ("tail") and pelte ("shield"), indicating the presence of the large keratinous shield at the tip of the tail. Currently, 8 genera are recognized comprising 47 species. i hope you get some info from this it took me a while to find it.

THe largest family of snakes is the colubrid family with over 1900 species.