Taxonomic review of the Ranatra gracilis group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of four new species Tran, A. D. Zettel, H. Raffles Bulletin of Zoology 2021 2021-02-25 69 45 70 78R82 Fabricius 1790 [890,1084,285,309] Insecta Nepidae Ranatra Animalia Hemiptera 2 47 Arthropoda species elongata   Diagnosis.Large species, body length: males 37–48, females 39–53; siphon long, ratio of siphon length: body length around 0.7–1.3; vertex in lateral view clearly lower than eye, without tubercle; flexor side of fore femur with a long and narrow tooth at distal 0.3–0.4 and a carina proximal to tooth, a pair of pre-apical teeth usually present (except  R. disparand  R. feana); posterior part of metasternum medially raised, with posterior margin convex; operculum of female clearly surpassing connexivum; connexivum of female produced posteriorly; male paramere with thick process on ventral side before hook, apical hook short and thick.  Species included.  Ranatra chinensis Mayr, 1865,  R. elongata Fabricius, 1790,  R. dispar Montandon, 1903a,  R. feana Montandon, 1903b, and  R. megalops Lansbury, 1972.  Note.For comparison between species and also key to species of this group, see Lansbury (1972).