<unk>  is a congenital disorder of the urinary bladder caused by failure of obliteration of proximal or distal part of the allantois, and the presentation of this anomaly is more common in children and rarer in adults. It is thought have been first described by Cabriolus in 1550.
Umbilical-urachal sinus
Meckelian groove
Nicomachus 
Clitoral hood
Kronig isthmus
Pinard horn
Oral torus
Phrygian cap 