The sublingual gland lies anterior to the submandibular gland under the tongue, beneath the mucous membrane of the floor of the mouth. They are drained by 8-20 excretory ducts. The largest duct, the sublingual duct (of Bartholin) joins the submandibular duct to drain through the sublingual caruncle. Most of the remaining small sublingual ducts open separately into the mouth on an elevated crest of mucous membrane, the sublingual fold (plica), caused by the gland and on either side of the frenulum linguae.