Cinygmula is a genus of flatheaded mayflies in the family Heptageniidae. There are at least 30 described species in Cinygmula.
Isonychia arida is a species of brushlegged mayfly in the family Isonychiidae. It is found in North America.
Heterocloeon curiosum is a species of small minnow mayfly in the family Baetidae. It is found in North America.
Callibaetis skokianus is a species of small minnow mayfly in the family Baetidae. It is found in the south half of Canada and the northeastern United States.
Hexagenia orlando is a species of common burrower mayfly in the family Ephemeridae. It is found in North America.
Paraleptophlebia debilis, the mahogany dun, is a species of pronggilled mayfly in the family Leptophlebiidae. It is found in North America.
Baetisca berneri is a species of armored mayfly in the family Baetiscidae. It is found in North America.
Drunella grandis is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in North America.
Heptagenia solitaria is a species of flatheaded mayfly in the family Heptageniidae. It is found in southwestern, northern Canada, and the western United States.
Arthroplea bipunctata is a species of flatheaded mayfly in the family Arthropleidae. It is found in North America.
Arthroplea is a genus of flatheaded mayflies in the family Arthropleidae. There are at least two described species in Arthroplea.
Paraleptophlebia guttata is a species of pronggilled mayfly in the family Leptophlebiidae. It is found in southeastern, northern Canada, and the eastern United States.
Drunella flavilinea is a species of spiny crawler mayfly in the family Ephemerellidae. It is found in Central America, North America. In North America its range includes southwestern, northern Canada, northern Mexico, and the western United States.
Maccaffertium vicarium is a species of flatheaded mayfly in the family Heptageniidae. It is found in North America.
Isonychia sicca is a species of brushlegged mayfly in the family Isonychiidae. It is found in Central America, North America. In North America its range includes southeastern Canada, and all of Mexico.
Siphlonurus typicus is a species of primitive minnow mayfly in the family Siphlonuridae. It is found in North America.
Ameletus vernalis is a species of combmouthed minnow mayfly in the family Ameletidae. It is found in southwestern Canada and the western United States.
Acentrella nadineae is a species of small minnow mayfly in the family Baetidae. It is found in the eastern United States.
Rhithrogena flavianula is a species of flatheaded mayfly in the family Heptageniidae. It is found in North America.
Siphlonurus rapidus is a species of primitive minnow mayfly in the family Siphlonuridae. It is found in North America.
