186 MOUKKiy SVSTEM. 



Genus 142. HELOPIIORUS. Leach. Elophorus. Fabr., Oliv., 



Latr., Gyll. 

 Ei/es sessile : thorax transverse. 



* Thorax and cli/tra furrowed. 



Sj). 1. Ilel. slagnaUs. Hydrophilus stagnalis. Marsh. 



Inhabits ponds, floating on the surface and walking on aquatic plants. 



** Thorax and elytra with elevated lines. 

 Sp. 1. Hel. nubiliis. Gyll. 



Genus 143. HYDROCHUS. Germar., Leach. Elophorus. Fabr., 



Illig., 4r. 



Eyes rather prominent: thorax elongated. 



Sp. 1. Ifyclr. cicindcloides. Hydrophilus cicindeloides. Marsh. 



Inhabits ponds, and may freijuently be found in the mud at the sides. 



Stirps 2. — Ch/pcus entire. 



Genus 144. OCIITIIEBIUS. Leach's Edinh. Enct/cl.—Zool. Misc. 

 vol. iii. ELOPiior.us. Fabr. IIydux.va. Latr., Illig. 

 Maxillari/ palpi with the middle and last joint slender and acute. 

 Sp. 1. Och. riparius. Leach. Hydrophilus impressus. Marsh. 



Genus 145. HYDllvENA. Kugellan, Leach. 

 Maxillary palpi with the last joint long and acuminated. 

 Sp. 1. Hi/d. Kugellani. Leach. Hydro, longipalpus. Marsh, 



Fam. XX. Hydrophilid.'e. 



Mandibles at their points bidentate : body oval or round : antenna ter- 

 minated by a club. 



Stirps 1. — Clypeus emarginate: sternum simple: antenna with six ar- 

 ticulations. 



Genus 146. SPERCHEUS. Fabr., Latr., Leach. 

 Sp. 1. Sper. sordidus. Spercheus sordidus. Fabr. Hydr. sordidus. 



Marsh. 

 Inhabits stagnant waters. 



Stirps 1. — Clypeus whole : sternum simple. 



A. Elytra icilh the apex whole. Scufellum small. 

 Genus 147. BEROSUS. Leach's Zool. Misc. vol. iii. 

 Body narrow before : tlnrrax convex : eyes rather prominent. 

 Sp. 1. Bcr. luridns of authors. 

 Inhabits ponds. 



