Sericostoma yuvarlakcay sp. n.

(Figs 40–44)

Material. Holotype male: Turkey, Muğla, Köyceğiz, Yuvarlakçay, Beyobası Village, 120 m, 36°55′N, 28°47′E, 24.v.1992, (CD: U-71); leg. and coll. SİPAHİLER.

Paratypes: 5 females: Same data as holotype .

General description. Antennae and maxillary palps brown, wings dark brown toblack, maxillary palps of male moderately large (Fig. 40); legs yellowish; length of each anterior wing of male 10.0 mm (n = 1), of female 12.0–13.0 mm (mean = 12.1 mm, n = 5).

Description of male genitalia (Figs 41–44). In lateral view, segment IX is roundly dilated anterolaterally at 70° angle. Preanal appendages short and clavate. In dorsal view, median part of segment X nearly parallel-sided and apically rounded, with small excision in middle. Lateral prolongations of segment X long; in lateral view, each with basal branch short, broadly triangular, curved slightly caudad, acute apically; mesoventral branch about half as long as dorsal branch and about as broad as dorsal branch, both tapering to acute apices, parallel to each other. Inferior appendages each with basal portion rather long; dorsal lobe rounded on apical edge and slightly longer than ventral lobe, ventral margin nearly straight; in ventral view, ventral branches straight, rather thick, apically rounded, pointed and abruptly curved mesad.

Diagnosis. Sericostoma yuvarlakcay sp. n. resembles S. flavicorne . The following differences are seen in the male genitalia: In S. flavicorne the branches of the lateral prolongations of segment X are narrower and the mesoventral and dorsal branches are more widely separated, and in dorsal view, the dorsal branches are dilated subdistally and each bearing a small, pointed projection on its inner edge. In contrast, in S. yuvarlakcay sp. n., the branches of the lateral prolongations are thicker, the mesoventral and dorsal branches are closer together than in S. flavicorne, and the dorsal branches are not as dilated subapically in dorsal view and are without any small, pointed projections.

Remarks. Sericostoma yuvarlakcay sp. n. inhabits a stream with rapidly flowing water.