S. Mahunka szerk.: Folia Entomologica Hungarica 49. (Budapest, 1988)

ratus and the ventral form of inferior appendages differentiate from all described species. I name this species according to the three teeth on the inferior appendages. Three: ba, tooth: rang in Vietnamese. A Fig. 7. Agapetus barang sp. n. - A= male genitalia, lateral, B= dorsal, C= ventral, D= phallic apparatus, lateral, E= fifth and sixth abdominal sternites, lateral, F= male wings Holotype 8. Hoa Binh, 8 km towards Da Bac, Vietnam, 30. 1. 1986, leg. Oláh. Singled along the shore vegetation of a third order stream. Paratypes: 1 o 2 <j> same data as holotype. 2 Ê, Hoa Binh, 20 km towards Tan Lac, Vietnam, 27. X. 1986, leg. Oláh. Singled along a small stream. Deposited at the Zoological Department, Hungarian Natural History Museum, Budapest. Right pair of wings mounted as dry microscopic preparation. Caustic potash-treated abdomen and the remaining part of the body are stored in a single selfstanding, airtight vial filled with 70% ethanol together with the untouched paratype. Agapetus halong sp. n. (Fig. 8) Male (in alcohol). General colour light brown. Wing membrane brown, hairs darker. Hyaline area on the fore wing not conspicuous, pterostigmal area well granulated. On hind wing Sc short ending before anastomosis, apex of R^ absent fork 1 present. Length and larg^ est width of fore wing 3.4-1.1, those of hind wing 2. 5-0. 7 mm. Fifth abdominal sternite with well-developed, unmodified ridge and the sixth sternite with a long apicomesal process. Male genitalia. Ninth abdominal segment synsclerotized with a long anteriolateral apo-; deme. Tenth segment cuculliform with an internal, slightly sclerotized sleeve surrounding the phallic apparatus. Phallic apodeme and phallocrypt tubiform but only the dorsum sclerotized especially the distal, deeply excised bilobed apex. The tube ventrally membranous, hardly visible. Aedeagus a long rod with an upcurving dilated apex. The unparied paramere stout heavily sclerotized shorter and tapering. Superior appendages downcurving. Inferior appendages subrectangular with an inner subapical blunt tooth continuing, in a heavily sclerotized black hump. Hind wing venation, structure of fifth and sixth abdominal sternites and the genital structure align this species to the "

rudis" subgroup and to Agapetus s. str. according to SCHMID's arguments. Phallic apparatus and inferior appendages specially formed. I name the species after the wonderful Ha Long archipelago situated nearby the Cat Ba Island.