HYDROPHILIDiE. HYDROPHILUS. 123 



on the disc towards the anterior margin: elytra large, elongate, each with 

 eight simple striae, the alternate interstices with a continuous series of irregu- 

 larly-impressed dots, which, with the striae, are deepest towards the apex, and 

 somewhat evanescent anteriorly : breast clothed with a yellowish pubescence ; 

 abdomen deep black, with luteous marginal spots ; legs pitchy, with the tarsi 

 rufescent towards the apex. Both sexes vary much in colour ; the female is 

 rather broadest. 

 The larva dusky, with smooth chestnut-coloured head, slender legs, and attenuated 

 tail : it feeds voraciously on mollusca, and changes in June beneath dung, 

 making a deep hole for the purpose : about August the imago appears : the 

 female deposits her eggs symmetrically, in a nest composed of a gummy 

 matter, which she spins out of her abdomen, in which receptacle they float 

 about till they are hatched. 



Not uncommon in many situations in the vicinity of the metro- 

 polis ; in a ditch by the junction of the Croydon and Surrey canals, 

 in brick-fields near Chelsea, ponds near Hampstead, Epping-forest, 

 &c. " River Cam, Bottisham-fen, &c." — Rev. L. Jenyns. " Com- 

 mon in ponds in Copenhagen-fields. " — Mr. Ingpen. " Whittlesea- 

 mere, June." — Messrs. Chant and Beniley. " Yaxley-mere." — 

 J. G. Children, Esq. " Glanville's Wootton."— J. C. Bale, Esq. 

 " Ealing and Paddington " — Rev. F. W. Hope. 



Genus CI. — Hydrophilus Auctorum, 



Maxillary palpi nearly as in Hydrous, but less robust, and the terminal joint 

 subfusiform : labrum transverse, emarginate : mandibles ciliated on the inner 

 edge, acute and bifid at the apex. Antennas nine-jointed; basal joint robust, 

 abruptly bent, and attenuated near its origin ; second elongate, and with the 

 three following, which are transverse, rather slender; the remainder forming 

 the club, the terminal joint of which is somewhat obtuse, and obliquely 

 truncate: head ovate; eyes small, reniform: elytra convex, broad poste- 

 riorly : sternum terminating in a slightly acute spine, which scarcely reaches 

 beyond the insertion of the posterior legs : legs not very stout ; the four pos- 

 terior tarsi compressed, ciliated on each side, and formed for swimming ; 

 anterior simple in each sex : claws dentate at the base, greatly incurved. 



The genus Hydrophilus differs from Hydrous by Laving the 

 labrum emarginate, the mandibles ciliated internally, without pro- 

 minent teeth, the antennae more obtuse at the apex, and the body 

 obtuse and somewhat dilated behind : from Spercheus and the fol- 

 lowing genera the acuminate sternum distinguishes it. The larva 

 somewhat resembles that of Gyrinus. 



Sp. 1. caraboides. Niger nitidus y elytris striis quinque punctatis, later alihus suh- 

 conjluentibus. (Long. corp. 8 — 10. lin.) 



