270 



1. Size larger; elytra with the interstices 

 coarsely rugose, black or purplish-black in 



both sexes D. HRACCATA, Scop. 



(niffra, F.) 



2. Size smaller; elytra with the interstices 

 finely rugose, black or purplish-black in male, 



coppery in female D. AFFINI8, R'unze. 



D. crassipes, F. (spinosa, Thorns.). Rather depressed, violaceous 

 or greenish. bronze, sometimes bronze with the elytra greenish at 

 margins, thorax usually coppery, under-side with thickly shining silvery 

 pubescence ; head finely and thickly punctured with the frontal furrows 

 deep ; thorax broader than long, finely strigose, with a strong central 

 furrow, and with the callosity near the anterior angles well marked ; 

 elytra with deeply punctured striae, apex truncate ; legs long, reddish 

 with the upper side of the apical portion of the femora, and the external 

 portion of the tibiae, metallic. L. 9-11 mm. 



Male with the fifth ventral segment of the abdomen truncate at apex, 

 the posterior femora stout and strongly bidentate, and the posterior 

 tibiae crenate dentate on their inner side. 



Female with the fifth ventral segment of the abdomen acuminate and 

 deflexed at apex, and the posterior femora armed with a sharp, but 

 less strong, tooth. 



On the leaves of the water lily (Nymphcea alba) and other aquatic plants; nof. 

 common, although found in some numbers where it occurs ; Kew, Weybridgc, Deal, 

 Brentford, Tottenham, Tonbridge ; New Forest; Burton-on-Trent; Mabberley, 

 Cheshire; Windermere ; Northumberland district, Prestwich Carr ; Scotland, local 

 and rare, Clyde and Argyle districts ; Highland lochs (Marker) ; Ireland, near 

 Dublin ; the species is very widely distributed, and probably occurs in many other 

 localities. 



D. dentata, Hoppe. Allied to the preceding, but smaller and 

 narrower, and more convex, and easily distinguished by the form and 

 sculpture of the thorax, which is as long as broad, and rather coarsely 

 punctured on disc ; colour aeneous or coppery with a greenish reflection, 

 under-side silvery ; head with deep frontal furrows, antennae long ; elytra 

 deeply punctate-striate, interstices diffusely strigose, apex truncate or 

 feebly emarginate ; legs ferruginous with the external portions more or 

 less aeneous. L. 7-9 mm. 



Male with the first ventral segment of the abdomen longitudinally 

 depressed in middle, and armed with two small tubercles, the posterior 

 femora armed with two sharp teeth, and the posterior tibiae crenate 

 dentate below middle. 



Female with the first ventral segment of abdomen evenly convex, and 

 the posterior femora armed with one rather sharp tooth, and one small 

 tooth, which is sometimes obsolete. 



On aquatic plants; rare; Chobham ; Sheerness; Shipley, near Horsham ; Knepp 

 Pond; Arundcl ; Tewkesbury ; Knowlc, near Birmingham ; Stephens gives as locali- 



