HYDROPHILID^. — LIMNEBIUS. 



119 



this family from the foregoing : the species of which it is composed 

 are more truly aquatic than the Helophoridse, and the typical species 

 swim with dexterity by means of their paddle-like tarsi : they prey 

 upon small aquatic mollusca and insects, in their first and final 

 states ; but their voracity is far inferior to that of the Hydrade- 

 phaga. . 



The British genera, which have received no accession to their 

 numbers since they were published by Dr. Leach, may be thus 

 known : 



99. LlMNEBIUS. 



f simplex ; ^truncata: 



' Elytra apice 1 



t integra; fsessiles: . . 104. Hydrobius. 

 Oculi < 



(.prominuli: 103. Berosus. 



f integer; 

 Sternum 



Clyjpeus \ |^spiniforme ; Antennae i acuminata: . 100. Hydrous. 



articulo ultimo < 



(obtuso: . . 101. Hydrophilus. 



I^emarginatus : ....... 102. Spercheus. 



Genus XCIX. — Limnebius, Leach. 



Maxillary palpi elongate, the basal joint minute, the rest of nearly equal length, 

 the second and third somewhat thickened at. the apex, the terminal rather 

 slender, slightly attenuated at each extremity. Antenna* short, slender at the 

 base, with an elongate six-jointed club : head ovate, moderate : eyes moderate : 

 thorax short, transverse, slightly convex, dilated at the sides : body somewhat 

 depressed; elytra rather oblong, truncate at the apex: scutellum broad; legs 

 moderate : tibiae slightly spinous : posterior tarsi ciliated. 



The truncate elytra and inferior bulk sufficiently point out this 

 genus at first sight; but other very evident characters of discri- 

 mination may be remarked, such as the depressed body, which 

 distinguishes it from Hydrobius and Berosus, and the simple ster- 

 num, by which it is known from Hydrous and Hydrophilus ; and 

 the integrity of the clypeus, which separates it from Spercheus. The 

 species have been much neglected, but from the examination of a 

 considerable number of specimens, the following appear to be 

 distinct. 



Sp. 1. ater. Plate XIV. f. 4. Atro-piceus,nitidissimus, thoracis lateribus elytro- 

 rumque marginibus dilutioribus, pedibus piceis, tibiis tarsisque pallidioribus. 

 (Long. corp. 1 — if lin.) 



Li. ater mihi. Steph. Catal.p. 58. A T o. 588. 



Ovate obtuse ; of a deep glossy pitchy-black, with the lateral margins of the 



