S. Mahunka szerk.: Folia Entomologica Hungarica 48. (Budapest, 1987)
granulated central part and less sclerotized lateral side-lobes bearring few setae. The most curious structural unit on the posterior surface of the fused basal part of tenth segment forms a heavily sclerotized and granulated small rounded plate clearly visible and specific in the less sclerotized sourrondings . Phallic apparatus very complex. Strongly developed dorsal process present with a slightly trilobed apex in dorsal aspect. Dorsal process continues anteriorly on the dorsum of the phallic apparatus in a similarly well-sclerotized, gradually narrowing band and laterally in a pair of similar bands. Parallel with this lateral arm tenons running on the posterior margin of the phallotheca. Latter large. Endotheca less developed. Parameres well visible, sclerotized rod deeply located in the phallotheca. At its distal end a thin strong spine originates in a ventroapical position. Aedeagus bilobed, the upper lobe forms a large plate in dorsal aspect, the lower lobe rod-like. Inferior appendages long, apical segments produce a ventral lobe. Fig. 7. Rhyacophila hangnia sp.n. A: male genitalia lateral, holotype, Tamdao; B: dorsal holotype, Tamdao; C: male genitalia dorsal, paratype Hoabinh; D: dorsal paratype Hoabinh Remarks: Due to difficulties and uncertainty in homologizing the fine structure of the tenth segment, I do not force to find the phylogenetic relatives of this species Besides the holotype, T have collected 8 o paratypes at Tam Dao in Vinh Phu Province and 6 o paratypes at Hoabinh in Ha Son Binh Privince. The animals from Ha Son Binh Province are smaller and darker and have minor structural differences in the genital structure as shown in my drawings. This is the smallest Rhy acophila species I have ever seen. T gave the name minor = hang nhi in Vietnamese. Type material: Holotype ó" Tamdao, Vietnam, at the foothill about 200 m a.s.l. 13.10.1986, singled, leg. OLÁH along a small tributary of the main stream. Deposited in the Zoological Department, Hungarian Natural History Museum, Budapest. Right pair of wing mounted as dry microscopic preparation. Caustic potash-treated abdomen and the remaining part of the body are stored in a single airtight self-standing glass vial filled with 70 % ethanol. 8 o 71 paratypes, Tamdao, Vietnam, at the foothill about 200 m a.s.l. 13.10.1986, singled, leg. OLÁH along a small tributary of the main stream. 6 d 1 paratypes, Hoabinh, Vietnam, toward Dabac, 21.10.1986, singled, leg. OLÁH, along a small side tributary.
