WPerlidae
WAcroneuria
WAcroneuria abnormis
WAcroneuria carolinensis
WAcroneuria internata
WAcroneuria lycorias
WAcroneuriinae
WAgnetina
WAgnetina annulipes
WAgnetina capitata
WAgnetina flavescens
WAttaneuria
WCalineuria
WCalineuria californica
WClaassenia
WClaassenia sabulosa
WDinocras
WDinocras ferreri
WEccoptura
WHesperoperla
WHesperoperla hoguei
WHesperoperla pacifica
WNeoperla
WNeoperla clymene
WNeoperla nigromarginata
WParagnetina
WParagnetina fumosa
WParagnetina immarginata
WParagnetina media
WPerla (stonefly)
WPerlesta
WPerlinella
WPerlinella drymo