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

Phallotheca strongly, endotheca very weakly devloped almost invisible. Phallobase with a sinuous dorsal process or rather a trough-like dorsal plate with sclerotized basement. Aedeagus present as a simple rod as long as the dorsal process. Parameres slender with ventral spines along the free part and ending in upcurving hairs. Both the aedeagus and parameres well sclerotized along their whole lengths. First segment of inferior appendages rather stout, second small and only slightly narrower at its base compared to the joining apical end of the first segment. Inner surface of the first segment bears numerous small stout spines. Remarks: This species with its golden wing irroration is a member of the "

anatina

" subgroup in the "

anatina" group and fits exactly with the series hydaspica

, dongkyapa and nagongpa having stout first segment with inner spines and somehow reduced second segment. Most close to R. hydas pica Schmid which is the most widely distributed species in the group populating the Hymalayas from Afganistan to Assam. There are, however, several well-defined differences. My species has a stouterand longer dorsal process on the ninth tergite. Preanal appendages regular not pointing and incurving than in hydaspica

. Dorsal process on phallobase sinuous and parameres with ventral spines. The widths at joining the first and second segments of inferior appendages almost equal so different in hydaspica

. I name this nice species in honour of Dr. S. MAHUNKA who accompanied me during my first visit to Vietnam. According to the result of the first two collecting trip this Rhyacophila species proved to be the most abundant and widely distributed one in the genus, at least in North Vietnam. Type material: Holotype d* Tamdao, Vietnam, 20.01.1986. Singled, leg. OLÁH along the main stream. 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 remaining part of the body are stored in a single airtight self-standing glass vial filled with 70 % ethanol. 4 cT paratypes. Tamdao, Vietnam, 20.01.1986. Singled, leg. OLÁH, 9 o* paratypes, Tamdao, Vietnam, 11.10.1986, singled, leg. OLÁH along the main stream. 11 ó

31 paratypes, Tamdao, Vietnam, 11.10.1986, singled, leg. OLÁH at the water-fall of the main stream. 1 o

71 paratype, Moc Chau, 24.10.1986, singled, leg. OLÁH along third order stream. 1 d* paratype, Moc Chau, 25.10. 1986, tight, leg. OLÁH. Male (in alcohol). General colour dark brown. Pleuron on thorax, legs except tibia and tarsus, abdominal sternites yellowish. Antenna! annulation visible. Wing membrane brown with brown pubescence. Costal area enlarged on fore wing, lighter and more densely covered with blackish hair. Hyaline area on cross-veins r-m, m-cu and on the costal ending of cu

2 pale rather large around r-m. Length and largest width of fore wing 7.0-2.4, those of hind wing 6.0-2.1 mm. Male genitalia. Medium long median process on seventh ster..He present. Ninth segment almost equally long both dorsal and ventral with a deep round triangular excision on either lateral margin. There is a transverse rim on the middle of dorsum and a longitudinal ventrolateral suture on both sides. Dorsal lobe of the ninth segment strongly developed with an abruptly narrowing short bilobed apex in dorsal aspect. Preanal appendages similarly long strips and completely fused with the dorsoapical lobe of the ninth segment, however, with a well-visible suture. Anal scelrites fused and almost as long as the dorsoapical lobe of the ninth segment and also bilobed in dorsal or ventral aspects. The apex somehow granulated. Anal sclerites with we 11-developed Interna! root. Apical band strip-like, sclerotized, with a membranous area extends beyond it. Tergal band sclerotized, slender, attached at the base of phallobase and developed a flat process, a sagittate process anterior to its juncture with the apical band. Phallotheca and especially endotheca small. Phallobase almost vertically directed downward. Aedeagus large, rod-like, rather stout, dominating the phallic apparatus. Parameres lost. Inferior appendages short, basal segment fused at their basis along its two-thirds length in an emarginate lobe beneath the aedeagus. Terminal segment short bilobed. Remarks: This species is easy to relate to the "

nigrocephala" group since it has a unique type of coupling between tenth tergite and phallic apparatus. It is, however, more difficult to find its closer relative within the group. It belongs to species without parameres and having fused inferior appendices. They dominate the group. All these species have a terminal segment

a

of inferior appendages not so deeply excised, except ligifera

, to which my species is most closely related, but differs in the details of dorsoapical lobes on the ninth tergite, of anal sclerites. Moreover, the inferior apRhyacophila janosi sp. n. (Fig. 4)