Definition that contains hagfishes
- suborder hyperotreta hagfishes as distinguished from lampreys
- myxiniformes hagfishes as distinguished from lampreys
- suborder myxiniformes hagfishes as distinguished from lampreys
- myxinoidea hagfishes as distinguished from lampreys
- suborder myxinoidei hagfishes as distinguished from lampreys
- myxinoidei hagfishes as distinguished from lampreys
- hyperotreta hagfishes as distinguished from lampreys