1856.] Entomological Papers. 537 



enlarged, rounded off and furnished with 3 strong teeth replaced by- 

 cilia on the inside, the inner lobe is conic and similarly provided 

 with teeth and cilia, but much thinner and finer. The maxillary 

 palpi are robust, the last joint is inflated at the base. The anten- 

 nal club is hairy, dark (whilst the remaining joints are yellowish), 

 conic and somewhat securiform, the 6th joint being inserted on one 

 side of the 7th. The legs are robust, the tibiae slightly curved, 

 obliquely truncated at the end, furnished with spines along the out- 

 side and with distant cilia along the inner. 



27. HydrocTius lacustris. N. 



H. elongatus, subdepressus, supra metallicus, iridescens, subtus 

 piceus, pedibus, antennis, palpis elytrorumque margine magis minusve 

 brunneis, mento cyaneo. Long. corp. m. 1 lin., f. multo major atque 

 robustior. 



Palpi, maxill. robusti art. ultimo elliptico leviter inflato. Mandi- 

 bular apice bifidae. Antennarum clava dense pilosa. Thorax oblonge 

 quadratus basin versus augustatus basi medio productus, cum 

 capite profunde punctatus. Elytra ad humeros oblique truncata, 

 apicem versus sat fortiter augustata, profunde striato-punctata. 

 Tibiae extus spinulosae. 



Specimina nonnulla in lacu Colomb. legi. 



The head is robust, broader than the thorax, the eyes large and 

 prominent. 



The femora, the last joint of the maxill. palpi, the mandibles and 

 the tarsal joints are dark towards the apex. The last abdominal 

 segment of the f. is furnished with a bifid hairy appendage. 



28. Hydrous rufiventris. iV. 



H. ovatus, convexus supra oleagino-niger, subtus obscure ferru- 

 gineus, pedibus dilute piceis, labro aeneo, reliquis oris partibus cum 

 clypeo testaceis. Long. corp. g. lin. 



Palpi maxill. articulis apicem versus abruptius incrassatis, art. 

 3° quarto sesqui longiore. Autennae art. 7-8 fortiter perfoliatis, 

 ultimo acuminato. Caput autice utrinque punctulorum serie sub- 

 seraicirculari et ad oculorum margiuem iuteriorem impressuin. 

 Thorax punctu lorum seriebus 4 lateralibus, 2 subapicalibus obliquis 



4 A 



