Lithosmylus Carpenter, 1943

Winterton, Shaun L., Martins, Caleb Califre, Makarkin, Vladimir, Ardila-Camacho, Adrian & Wang, Yongjie, 2019, Lance lacewings of the world (Neuroptera: Archeosmylidae, Osmylidae, Saucrosmylidae): review of living and fossil genera, Zootaxa 4581 (1), pp. 1-99 : 37

Lithosmylus Carpenter, 1943

Type species. Osmylus columbianus Cockerell, 1908: 758 (by original designation).

Diagnosis. Wings oval; FW costal area broad basally, subcostal veinlets closely spaced and mostly shallowly forked in both wings, veinlets simple at wing base and distally; first branch of RP originating near origin of RP on RA; FW RP with 16 branches, HW with 17 branches; both wings with outer gradate series well developed, inner gradate series absent, radial crossveins numerous in basal half of wing, slightly more irregularly arranged in HW; M forked slightly distal to origin of RP1; MA and MP with 2–4 branches distally in both wings; CuA and CuP strongly pectinately branched in both wings with shallow end-twigging very close to wing margin, FW with six branches in CuA and nine branches in CuP, HW with seven branches in CuA and 12 branches in CuP; FW A1 with seven pectinate branches, HW A1 with four pectinate branches; FW A2 with four pectinate branches, two in HW; A3 simple in both wings.

Comments. The venation of this fossil genus is relatively typical for Osmylinae and we agree with its placement in this subfamily by Lambkin (1987) and Wang et al. (2011a), although considering the wing venation similarity, Carpenter (1943) unsurprisingly regarded it as belonging to Kempyninae . Only the wings are known.