(Figs 4–6, 11)
Limnobia placida Meigen, 1830: 275 (description).
Limnobia hyalipennis Zetterstedt, 1851: 3842 (description).
Limnophila ultima Osten Sacken, 1860: 238 (description), Fig. 26 (male terminalia) – syn. nov.
Neolimnophila placida: EDWARDS (1938): 99 (diagnosis), Text-Fig. 18b (male terminalia); SAVCHENKO (1982): 19 (redescription), Fig. 8 /2 (male terminalia); PODENAS et al. (2006): 112, Fig. 29.5 (male terminalia) [copied from SAVCHENKO 1982]
Neolimnophila ultima: ALEXANDER (1966): 430 (diagnosis), Fig. 47B (wing).
Material examined (7 ♁♁ 17 ♀♀). U.S.A.: INDIANA: Jefferson Co., 15.ix.1934, 2 ♁♁ (J. S. Rogers leg.) (JSOC). CZECH REPUBLIC: MORAVIA: Moravskoslezské Beskydy Mts [= Beskydy Mts], Prostřední Bečva (600 m), 7.vi.1994, 1 ♁; Lazníky nr. Přerov, 30.v.1991, 1 ♀, 8.vi.1991, 3 ♁♁ 1 ♀, 9.vi.1991, 1 ♁ (all J. Starý leg.); Lešná nr. Zlín [= nr. Gottwaldov], 19.vii.1977, 3 ♀♀ (J. Starý leg., at light), 17.v.1979, 1 ♀ (V. Elsner leg., light trap), 6.vi.1980, 1 ♀ (J. Starý leg., at light) [listed by STARÝ (1986)], 4.ix.1985, 1 ♀ (V. Elsner, at light), 20.v.1987, 1 ♀ (V. Elsner leg., at light); Hrobice nr. Zlín, 19.viii.1980, 1♀ (V. Elsner leg., at light), 24.viii.1981, 1 ♀ (J. Starý leg.), 14.vii.1982, 1 ♀ (J. Starý leg., at light) [listed by STARÝ (1986)]; Bílé Karpaty Mts, Javorník, “Machová”, 29.ix.1998, 1♀ (J. Starý leg., at light) (all JSOC). POLAND: Tuszyn nr. Lódż, 4.–6.vii.1980, 1 ♀, 7.vii.1980, 1 ♀, 3.viii.1980, 1 ♀ (B. Soszyński leg.) (JSOC). SLOVAKIA: Poľana Mts, Čierny Potok (700 m), 8.vi.1999, 1 ♀ (J. Starý leg., at light) [listed by STARÝ (2009)] (JSOC).
Material not examined by the author (3 ♁♁). Based on my drawings and diagnoses, D. I. Gavryushin (ZMUM) kindly identified some specimens, previously labelled mostly as N. placida. Those belonging to N. placida in the present concept are listed below, others, as N. alaskana, are listed under the latter species. – RUSSIA: NORTH EUROPEAN RUSSIA: Arkhangelsk env.(35 m), 64.525117°N, 40.719567°E, 5.viii.2011, 1♁ (D. I. Gavryushin leg.) (ZMUM); Leningrad Region [= oblast], Vsevolozhskiy District, Jukki village, 13.vii.1933, 1 ♁ (A. A. Stackelberg leg.) (ZISP). NORTHWEST EUROPEAN RUSSIA: Pskov Region, Plyusskiy District, Kharlamova Gora village, 9.viii.1891, 1 ♁ (F. D. Pleske leg.) (ZISP).
Diagnosis. Antenna rather short, with verticils short, longest ones shorter than their respective segments. Dorsum of thorax heavily suffused with bluish dark grey pruinosity, prescutum with four brown stripes. Wing comparatively narrow, width-length ratio about 1: 3.8. Male terminalia with two spines at base of gonocoxite, ventral spine about one third length of dorsal one, outer gonostylus comparatively stout and short, and with paramere narrow, its distal outer extension conspicuous. Wing length 5.8–8.6 mm.
Redescription. Male. Head dark brown, suffused with bluish dark grey pruinosity on frons and vertex. Palpus and rostrum dark brown. Antenna dark brown throughout, comparatively short, shorter than that of N. carteri and N. alaskana, not reaching to base of wing, with scape greyish pruinose. Flagellum consisting of basal fusion element and subsequent 10 long-ovoid flagellomeres, with verticils sparse and short, longest ones shorter than their respective segments.
Thorax generally dark brown, heavily suffused with bluish dark grey pruinosity, especially on dorsum, sometimes indistinctly paler on anterior paratergite and posterolaterally on scutal lobes. Prescutum with four brown stripes. Wing comparatively narrow, width-length ratio about 1: 3.8, sometimes with faintly indicated stigma. Venation usual for Neolimnophila. Sc1 ending opposite or slightly before fork of Rs. R2 (cross-vein r) at or at most its own length before or slightly beyond fork of R3+4. R3 from shorter to subequal in length to R3+4. Latter vein slightly arched. Cross-vein m-cu at from one fourth to one third length of discal cell (Fig. 11). Halter pale on stem, weakly infuscated on knob. Legs brown, with setae on femora comparatively short, decumbent, less than diameter of femur.
Abdomen dark brown. Male terminalia (Figs 4–6). Tergite 9 interrupted medially. Gonocoxite with two spines at base: longer, positioned dorsally, subequal in length to corresponding spine in N. carteri and N. alaskana, about one third length of gonocoxite; shorter about one third length of dorsal spine, positioned more ventrally and medially. Both spines with delicate membranous scales distally. Outer gonostylus shorter than that in N. alaskana and stouter than in N. carteri and N. alaskana, from base evenly slightly narrowed distally for about two thirds its length, slightly concave before apical hook, hook microscopically serrate at outer margin. Paramere not as broad as in N. carteri and N. alaskana, truncate at apex, conspicuously extended disto-laterally into spinous point.
Female resembling male in general appearance, including length and structure of antenna and outline of wing. Female terminalia not essentially different externally from those of other species.
Distribution. Canada, U.S.A. (as far south as Mississippi and Georgia); Europe, including European Russia; West and East Siberia, Far East of Russia; Kazakhstan; Mongolia; Japan.