Rheotanytarsus rivulophilus Kawai et Sasa

(Fig. 38)

Rheotanytarsus rivulophilus Kawai et Sasa, 1985: 21, Fig. 7.

Tanytarsus ginzanquartus Sasa et Suzuki, 1998: 16 –17, Fig. A8. [Holotype 347: 048.] Syn. nov.

Tanytarsus ginzanquartus has the gonostylus abruptly tapered in apical half, the anal point without patches of short spines between the anal crests, and the median volsella with lamelliform setae. These characters indicate that T. ginzanquartus should be transferred to the genus Rheotanytarsus Thienemann et Bause. The elongate lamelliform setae of median volsella are curved medially and extend well beyond the apex of inferior volsella (Fig. 38), similar to those of R. rivulophilus Kawai et Sasa.