Three New Species of the Genus Caenis from Hong Kong,China (Ephemeroptera:Caenidae)

Three new species of the genus Caenis (Ephemeroptera,Caenidae),Caenis aspera sp.nov.,Caenis bicornis sp.nov.and Caenis lubrica.sp.nov.,are described from Hong Kong,China.All type specimens are deposited in the Insect Collection of Department of Entomology,South China Agricultural University,China.