Limentinus is the Roman God whose responsibility was to protect the threshold of the house. His associates are Cardea

Cardea

Cardea or Carda was the ancient Roman goddess of the hinge , Roman doors being hung on pivot hinges. The Augustan poet Ovid conflates her with another archaic goddess named Carna, whose festival was celebrated on the Kalends of June and for whom he gives the alternative name Cranê or Cranea, a nymph...

 and Forculus.

The whole door is protected by Janus

Janus

-General:*Janus , the two-faced Roman god of gates, doors, doorways, beginnings, and endings*Janus , a moon of Saturn*Janus Patera, a shallow volcanic crater on Io, a moon of Jupiter...

. Limentinus is mentioned by St. Augustine

St. Augustine

-People:* Augustine of Hippo or Augustine of Hippo , father of the Latin church* Augustine of Canterbury , first Archbishop of Canterbury* Augustine Webster, an English Catholic martyr.-Places:*St. Augustine, Florida, United States...

as a protector of the threshold and may have been responsible for preventing Silvanus from entering the household if a certain ceremony was performed over children at their birth. Though he may not have been the original cause of the carrying the bride over the threshold, that would be of Syrian origin, some believe it is so.