118 MANDIBULATA. — COLEOPTERA. 



dilated, somewhat unequal; the disc thinly but finely punctured: elytra 

 slightly convex, piceous or brownish-black, thickly punctate-striated: legs 

 pale rufescent ; antenna? and palpi paler, with the tips dusky. 

 The size and colour vary considerably. 



I have occasionally taken this insect in ponds in the neighbour- 

 hood of London, especially on Hampstead-heath. " Netley, 

 Salop, and Tenbury." — Rev. F. W. Hope. " Glanville's Wootton, 

 and Parley-heath." — /. C. Dale, Esq. 



Sp. 2. pusilla. Plate XIV. f. 3. Subovata, saturate nigra nitida, elytris obsolete 



punctato-striatis, pedibus rujis. (Long. corp. f — I lin.) 

 Hy. pusilla mihi. Steph. Catal. p. 58. No. 586. 



Broader and shorter than the preceding, of a darker colour, &c. Subovate ; deep 

 glossy black : head obscurely punctured, the crown slightly rugose : thorax 

 very finely but thickly punctured, with a slight fovea near each posterior 

 angle : elytra rather obsoletely but thickly punctate-striated : legs rufous : 

 antennae and palpi rufescent, dusky at the apex. 



This is probably the Hydrama nigrita of Midler. See Germar Coleopterorum 

 Species Nova, &c. p. 93. 



Taken near London. "Netley and Tenbury." — Rev. F. W. 

 Hope. " Midgley-moor near Halifax."" — Mr. Gibson. " River 

 Cawdor near Carlisle, and in a marsh near Ashburton, Devon- 

 shire." — Dr. Leach. 



Sp. 3. minutissima. Ovata, nigro-picea, thorace canaliculato, elytris lasvibus, 



antennis pedibusque pallidis. (Long. corp. ^ lin.) 

 El. minutissima? Gyllenhal? — Hy. minutissima. Steph. Catal. p. 85. No. 



587. 



Ovate pitchy-black : head glossy, obtuse; eyes rather large, globose : thorax black, 

 shining, convex, behind with a slight channel in the middle, and a minute 

 fovea on each side : elytra ovate, convex, smooth, glossy pitchy-black, the 

 apex paler: body black: legs, antenna?, and palpi pale. 



1 have a single indigenous species agreeing with the above description. 



I am not aware of the exact locality of this insect. 



Family XIV.— HYDROPHILIDtE, Leach. 



Antenna? generally nine- rarely six-jointed, perfoliate-clavate, the club distinctly 

 cleft. Mandibles bidentate at their extremities ; maxillary palpi very long, 

 usually filiform ; body oval or somewhat rounded, frequently nearly globose : 

 thorax short, transverse: tibia slightly spinose; tarsi five-jointed, filiform, 

 the posterior sometimes ciliated, the basal joint minute, the second longer 

 than the rest. 



The bidentate mandibles enable us with facility to discriminate 



