This family, althougn quite distinct, is closely allied to the two which follow— the Myrmosidœ and the Mutillidœ— and it will probably be difficult for the student to separate at once the wingless females from some in the families mentioned. Some authorities, having been unable to find good characters to separate these wasps, have classifed all together as a single large family under the name Mutillidœ; but I think incorrectly so.