Azilia leucostigma Mello-Leitão 1941 considered by Mello-Leitão as a metine (Tetragnathidae), is transferred to the gnaphosoid family Gallieniellidae, as the type species of the new genus Galianoella. The obliquely depressed endites, the flattened irregular posterior median eyes, and the conical anterior lateral spinnerets retaining a sclerotized distal ring, among other characters, clearly place the new genus in the family Gallieniellidae. Galianoella leucostigma is the only gallieniellid so far recorded from the Americas. This species has a specialized ant-preying behavior. Ant-preying may prove to be characteristic for all the family, as it was suspected in the Madagascan Gallieniella; and it may be associated with the modified chelicerae typical of the family.