title: Status of the enigmatic Oriental genus Rhithrogeniella Ulmer, 1939 (Ephemeroptera, Heptageniidae).
abstract: Based on historic collections and new material from Sumatra and Java, the species Rhithrogeniella ornata Ulmer, 1939, type species of the genus Rhithrogeniella, is reinvestigated. The nymph is described for the first time and is closely related to the continental Southeast Asian species Rhithrogeniella tonkinensis Soldán and Braasch, 1986. Rhithrogeniella belongs to the subfamily Ecdyonurinae, and is related to the genera Nixe Flowers, 1980 and/or Paracinygmula Bajkova, 1975 based on characters of the nymphal stage. Species described from Taiwan in the genus Nixe are transferred to the genus Rhithrogeniella: Rh. littoralis (Kang and Yang, 1994) comb. n., Rh. mitifica (Kang and Yang, 1994) comb. n. and Rh. obscura (Kang and Yang, 1994) comb. n.
authors.affiliation: Zoologisches Museum und Biozentrum Grindel, Martin-Luther-King-Platz 3, D-20146 Hamburg, Germany ; Museum of Zoology, Palais de Rumine, Place Riponne 6, CH-1005 Lausanne, Switzerland.
authors.forename: Michel
authors.initials: M
authors.lastname: Sartori
keywords: Java; Nixe; Paracinygmula; Rhithrogeniella ornata; Rhithrogeniella tonkinensis; Sumatra; new combinations