HEMIPTERA HETEROPTERA. 163 



Fam. 3. GERMD^E. 



Gerridae, Serv. Hist. Hem. 418— Hydrobatida, Slal, Hem. Afr. iii. 168— 

 Hydrometrae, Fieb. Eur. Hem. — Hydrometridae, Dougl. and Scott, 

 Hem. 40. 



A. Fore tibiae with a distinct apical tooth. 



a. Abdomen very short. - - - - 3. Halobates. 



b. Abdomen almost as long as the thorax. - -2. Ptilomera. 



B. Fore tibiae with no distinct apical tooth. - - 1. Gerris. 



Genus 1. GERRIS. 



Gerris, Latr. Gen. iii. 133. Schutn. Beilr. 11. Serv. Hist. Hem. 414 — 

 Hydrometra, Fabr. Syst. Rhyn. 256. Barm. Ramb. Fieb. Eur . 

 Hem. 106. Dougl. and Scolt, Hem. 557 — Tenagogonus, Stal, Ofv. 

 K. V. Ak. Fork. x. 263; Hem. Afr. iii. 168 — Limnoporus, Stal, Ofv. 

 K. V. Ak. Fork. xxvi. 398— Limno^onus, Stal, Ofv. K. V. Ak. Fork. 

 vii. 132— Limnotrechus, Stal, Ofv. K. V. Ak.Forh. xxv. 398— Hygro- 

 trechus, Stal, Ofv. K. V. Ak. Forh. xxv. 398. 



Europe. 



1. Gerris rufoscutellata. 



, Stall, Pun. pi. 15, f. 108 — Gerris rufoscutellata, Lair. Gen. iii. 134. 

 Schum. Plot. pi. 3, f. 1,2; pi. 4, f. 1,14 — 19 — Hydrometra lacustris, 

 Fall. Hem. 159 — Hydrometra rufoscutellata, H.-Sch. Warn. Ins.ix. 

 69, pi. 300, f. 924. Fieb. Eur. Hem. 106 — Limnoporus rufoscutellalus, 

 Stal. 



Europe. 



2. Gerris paludum. 



Gerris paludum, Fabr. Ent. Syst. iv. 188. Schum. Beitr. Plot. 29, pi. 4, 

 f. 5—13. Brull. Hist. Nat. Ins. ix. 302. Blanch. Hist. Nat. Ins. 

 iii. 97. Serv. Hist. Hem. 417 — Hydrometra paludum, Fabr. S?/st. 

 Rhyn.258. Zett. Ins. Lapp. 281. H.-Sch. Wanz. Ins. ix. 67, pi. 300, 

 f. 926. Burm. Handb. Ent. ii. 210. Fieb. Eur. Hem. 106. Flor, 

 Rhyn. Liv. i. 732. Dougl. and Scolt, Hem. 559 — Hygrotrechus 

 paludum, Stal. 



a — n. England. 

 o, p. South France. 



3. Gerris Najus. 



Ciraex Najus, Deg. Ins. iii. 311, pi. 16, f. 8,9 — Gerris aptera, Wimm. 

 Schuml. Plot. 34, pi. 4, f. 4, 20—24 — Genis canalium, L. Duf. Rech. 

 Hem. 69, pi. 5, f. 59. H.-Sch. Wanz. Ins. pi. 300, f. 925, K. L, M. 

 Serv. Hist. Hem. 418 — Hydrometra aptera, H.-Sch. Wanz. Ins. ix. 

 69, pi. 300. f 925— Hydrometra Najus, Fieb. Eur. Hem. 107. Dougl. 

 and Scott, Hem. 560 — Hygrotrechus Najus, Stal. 



a, b. Fiance. 



