S. Mahunka szerk.: Folia Entomologica Hungarica 48. (Budapest, 1987)

ed anal sclerite which has no internal root. Tergal band also lacking. Anal sclerites widely separated in ventral aspect and rectangular. Phallotheca strongly, endotheca weakly developed. Phallobase produced in a strong dorsal process with a highly sclerotized basement and less sclerotized dor somarginal rim forming together a long trough. Aedeagus forms a simple rod as long as the first segment of the inferior appendages. Parameres of similar length and very conspicuously spatulate forming a brush-like arrangement of backward directed hairs. Inferior appendagas long, slender. Terminal segment only slightly narrower at base and weakly tapering distally. Remarks: This species belongs to the "falcifera" subgroup of the "anatina" group and differs from falcifera

, triangularis and tamdaona in the short bifid apex of the dorsal process on the ninth segment, in the sinuate apex of the preanal appendages and in having the remarkable spatulate paramere. The capital of Ha Son Binh Province, a center of my collecting trips, inspired me to name this black Rhyacophila species. Fig. 1. Rhyacophila hoabinha sp.n. A-male genitalia, lateral; B: dorsal; C: tenth segment, posterior; D: male wings Type material: Holotype o". Hoabinh, Vietnam, 31.1.1986, light, leg. OLÁH on white sheet with mercury vapour lamp of 250 W. Deposited in the Zoological Department, Hungarian Natural History Museum, Budapest. Right pair of wings mounted as dry microscopic preparation. Caustic potash-treated abdomen and the ramaining part of the body are stored in a single airtight self-standing glass vial filled with 70% ethanol. 4 d* 3 °. paratypes. Hoabinh, Vietnam 31.1.1986, light, leg. OLÁH. 1 o" 1 ? paratypes Hoabinh, 20 km towards Tanlac, 27.10.1986, singled, leg. OLÁH along a third order stream.