S. Mahunka szerk.: Folia Entomologica Hungarica 49. (Budapest, 1988)
Ninth segments forms a long tube armed with a long slender sclerite with a long apodeme. The small tenth segment terminates in a pair of slender, two-segmented cerci. According to the hind wing venation and the structure of the fifth and sixth abdominal sternites this species belongs to the " rudis" group of the Synagapetus subgenus established ; by ROSS. The species in this group have been further divided into two categories, the "rudis " subgroup in which the tenth tergite is composed of single lobes and the " mitis" subgroup in '> which the lobes of the tenth tergite bear an upcurved process arising either at the end of the lobe or from the base of the ventral margin 1 . Although my species has a ventral branch on the tenth segment without an upcurving ending, the braching itself relates this species to the " mitis" subgroup. The other subgroup has a simple compact tenth tergite. Nevertheless, this is a rather isolated species within the subgroup and its final place, must be confirmed. I named this unique species in honour of DANG NGOC THANH, director at the National Centre for Scientific Research of Vietnam who provided generous help during my visits. Holotype S. Hoa Binh, Vietnam, 8 km from Hoa Binh in the direction of Da Bac, singled at small stream, 30.1. 1986, leg. Oláh. Allotype g, same data as holotype. Paratype g, same data as holotype. Deposited at the Zoological Department, Hungarian Natural History Museum, Budapest. Right pair of wings of holotype S mounted as dry microscopic prépara- j tion. Caustic potash-treated abdomen of holotype and allotype and the remaining part of their body are stored in a single airtight vial filled with 70 % ethanol together with the untouched g paratype. Agapetus gotgian sp. n. (Fig. 2) Male (in alcohol). General colour brown. Wing membrane brown, hairs darker. On fore wing small whitish hyaline area at the costal tip of Sc, at cross-vein r, r-m, below the stem M and along the costal ending of Cun. On hind wing R, ending on Sc somewhat beyond Fig. 2. Agapetus gotgian sp. n. - A= male genitalia, lateral, B= dorsal, C= ventral, D= phallic apparatus, E= fifth and sixth abdominal sternites, lateral anastomosis, R^ is almost obsolete. Crossjvein r linking and R2+3 present and well developed. Sc long, ending on C well beyond anastpmosis, fork 1 absent. Length and largest width of fore wing 3. 5- 1. 2, those of hind wing 2. 8-0. 9 mm. Fifth abdominal sternite with an unmodified lateral ridge, sixth sternite with a medium-sized narrow apicomesal process. Male genitalia. Ninth abdominal segment ring-like with lateral convexity both anterior! ly and posteriorly and with a apicomesal triangular process. Tenth segment composed of the upper triangular lobe and the upcurving lower branch. Triangular lobe has a small tooth on its tip more sclerotized and outward directed in dorsal aspect. The lower branch originates from the basement of the tenth segment and confluent with the superior appendage. The caudad directed rod-like first part bears a small spine at the tip before the suture separating the second back curving part which is dorsoventrally flattened. The second part ends in a
