Nine angiomatous malformations situated on the outer surface of the dura and one situated in the pelvis, from which draining veins pierced the dura and joined the coronal venous plexus are described. The clinical manifestations and myelographic appearances are similar to those of the majority of intradural angiomatous malformations. This suggests that neurological deficiences with both types of malformation are usually due to raised venous pressure with secondary ischaemic hypoxia.