170 ADEPiiAQA. [QjuJamhtis. 



dimorphic, one form sliiuiug and jJuiictured as in male, the other very 

 dull and opaque, with the elytra uniformly and finely punctured, with 

 the three rows of punctures obsolete ; this form is rather rare, and is the 

 lineellus, Gyll. Long. 5, lat. 2|- mm. 



Ponds, &c.; local; rather common in the London district, Lee, Lewisham, Penge, 

 Pcckhaui, Wimbledon, &c. ; Norfolk; Shropshire; Devonshire; Swansea; Askham, 

 near York ; Scotland, rare, Lowlands, Solway district ; Ireland, near Waterford 

 (Power) and Killarney (WoUaston). This species stretches right across Siberia into 

 Korth Americii. 



DERONECTES, Sharp. 



This genus comprises about forty-five species, which mostly inhabit 

 Europe and the Mediterranean regions, a few being found in North 

 America ; we possess five species as British, which are among the most 

 conspicuous of our indigenous Hydropori. 



I. Upper surface very finely punctured, with thickly 

 scattered larger punctures, uuicolorous dark 



bi-ownish-red (head and base of elytra lighter) . . J). l-kTXSS, Steph, 



II. Upper surface uniformly and very finely punc- 



tured. 

 i. External border of elytra furnished near apex 

 with a small sharp tooth. 



1. Upper surface covered with close golden 

 pubescence ; dark markings mostly in lines ; 



thorax broader at base than at apex . . . . D. assimilis, Payk. 



2. Upper surface almost smooth ; dark markings 

 mostly in patches ; thorax almost as broad at 



apex as at base D. DEPRESSUS, jP. 



ii. External border of elytra without tooth near 

 apex. 



1. Sides of thorax and elytra strongly rounded, 

 forming a distinct angle at junction; disc of 



thorax not marked with black D. 12-pirsTULATUS, 01. 



2. Sides of thorax and elytra together forming a 

 continuous outline ; disc of thorax with black 



markings D. geiseo-STRTAtus, Be O. 



D. latus, Steph. Broad, oval, convex, but rather depressed on disc, 

 dull, very slightly pubescent, ferruginous or fusco-ferxuginous, elytra 

 darker with lighter base, antennse and legs reddish testaceous ; entire 

 upper surface very finely punctured with numerous large and deep 

 punctures irregularly distributed over its whole extent, but more plain 

 on elytra ; elytra with traces of raised lines ; front and middle tarsi broad 

 in both sexes, but more dilated in male ; in the female there is a short 

 raised longitudinal fold near the outer edge of the elytra at some distance 

 from apex. Long. 4^, lat. 2| mm. 



Rare; in clear or running water among shingle and stones, &c. Stephens' original 

 specimens were from Mai'ton Lodge, Yorkshire; Hollingtou, near Hnstings (Butler) ; 

 Tilgate Forest (Power) ; Northumberland district (Ouseburn, Devil's Water, Moors 

 near lianercost) ; Scotland, rare, in rapid waters. Lowlands, Tweed, Forth, Solway 

 and Moray districts (Polmont (near Glasgow) iu some numbers (Power)); banks of 

 Almond, near Broxbourne (Sharp). 



