A remarkable Aulacus Jurine, 1807, A. ceciliae Turrisi, sp. nov., is described from Laos and A. bituberculatus Cameron, 1899 from India is redescribed from the type material, which has been recently rediscovered. For the latter species, a lectotype is formally designated. Both species are very characteristic due to the presence of two tooth-like processes on the vertex, an autapomorphic feature probably related with the endoxylic bionomy. References to the other two Oriental species of Aulacus, A. philippinensis (Kieffer, 1916) and A. sinensis He & Chen, 2007 and a key to all four species of the genus presently known for the Oriental Region are provided.