Cyclorrhapha is an unranked taxon within the infraorder Muscomorpha

Muscomorpha

The Brachyceran infraorder Muscomorpha is a large and diverse group of flies, containing the bulk of the Brachycera, and, in fact, most of the known flies. It includes a number of the most familiar flies, such as the housefly, the fruit fly and the blowfly. The antennae are short, usually...

. They are called "Cyclorrhapha" ('circular-seamed flies') with reference to the circular aperture through which the adult escapes the puparium. This is a circumscriptional name

Circumscriptional name

Circumscriptional names are taxon names used above family-group level that are not ruled by ICZN and are defined by the particular set of members included, not the number of species....

 that has significant historical familiarity, but in the present classification, this name is synonymous with the more recent "Muscomorpha

Muscomorpha

The Brachyceran infraorder Muscomorpha is a large and diverse group of flies, containing the bulk of the Brachycera, and, in fact, most of the known flies. It includes a number of the most familiar flies, such as the housefly, the fruit fly and the blowfly. The antennae are short, usually...

"; details and reasoning are presented here.